Delivery Server API Documentation

Delivery server management endpoints for creating, updating, deleting, retrieving and verifying SMTP delivery servers. These endpoints are admin-only and manage the SMTP servers used to send email campaigns.

Create a Delivery Server

POST /api/v1/deliveryserver.create

API Usage Notes

• Authentication required: Admin API Key
• v1 REST alias: POST /api/v1/deliveryserver.create. Legacy access via /api.php is also supported

Request Body Parameters:

Parameter	Type	Required	Description
Command	String	Yes	API command: deliveryserver.create
SessionID	String	No	Session ID obtained from login
APIKey	String	No	API key for authentication
DeliveryServerName	String	Yes	Name of the delivery server
SendMethodSMTPHost	String	Yes	SMTP server hostname or IP address
SendMethodSMTPPort	Integer	Yes	SMTP server port (e.g., 25, 587, 465)
SendMethodSMTPSecure	String	Yes	Security protocol: "false", "ssl", or "tls"
SendMethodSMTPTimeout	Integer	Yes	Connection timeout in seconds (must be numeric)
SendMethodSMTPAuth	Boolean	Yes	Whether SMTP authentication is required: true or false
SendMethodSMTPUsername	String	Conditional	SMTP username (required if SendMethodSMTPAuth is true)
SendMethodSMTPPassword	String	No	SMTP password
DomainSettings_LinkTracking	String	Yes	Domain for link tracking (e.g., "track.example.com")
DomainSettings_OpenTracking	String	Yes	Domain for open tracking (e.g., "open.example.com")
DomainSettings_MFrom	String	Yes	Mail From domain (e.g., "bounce.example.com")
DomainSettings_EnforcedFrom	String	No	Enforced From email address (must be valid email format)
SenderInfoAsMFrom	String	No	Use sender info as MFrom: "Enabled" or "Disabled" (default: "Disabled")
SenderInfoAsFrom	String	No	Use sender info as From: "Enabled" or "Disabled" (default: "Disabled")
SenderRotation	String	No	Enabled to store Domains.sender_rotation = true (default false). Before v5.9.6 this parameter was accepted by deliveryserver.update only and silently dropped on create
SenderRotation_Settings	String	No	Stored as Domains.sender_rotation_settings. Before v5.9.6 this parameter was accepted by deliveryserver.update only and silently dropped on create

Example Request

curl -X POST https://example.com/api.php \
  -H "Content-Type: application/json" \
  -d '{
    "Command": "deliveryserver.create",
    "SessionID": "admin-session-id",
    "DeliveryServerName": "Primary SMTP Server",
    "SendMethodSMTPHost": "smtp.example.com",
    "SendMethodSMTPPort": 587,
    "SendMethodSMTPSecure": "tls",
    "SendMethodSMTPTimeout": 30,
    "SendMethodSMTPAuth": true,
    "SendMethodSMTPUsername": "smtp_user",
    "SendMethodSMTPPassword": "smtp_password",
    "DomainSettings_LinkTracking": "track.example.com",
    "DomainSettings_OpenTracking": "open.example.com",
    "DomainSettings_MFrom": "bounce.example.com",
    "DomainSettings_EnforcedFrom": "noreply@example.com"
  }'

Success Response

{
  "Success": true,
  "ErrorCode": 0,
  "ErrorText": "",
  "DeliveryServerID": 123
}

Error Response

{
  "Success": false,
  "ErrorCode": [1, 2, 3],
  "ErrorText": ["Missing deliveryservername", "Missing sendmethodsmtphost", "Missing sendmethodsmtpport"]
}

Error Codes

0: Success
1: Missing deliveryservername
2: Missing sendmethodsmtphost
3: Missing sendmethodsmtpport
4: Missing sendmethodsmtpsecure
5: Missing sendmethodsmtptimeout
6: Missing sendmethodsmtpauth
7: Missing sendmethodsmtpusername
8: Missing sendmethodsmtppassword
9: Missing domainsettings_linktracking
10: Missing domainsettings_opentracking
11: Missing domainsettings_mfrom
12: Missing domainsettings_enforcedfrom
13: Invalid sendmethodsmtpsecure value (must be: false, ssl, tls)
14: Invalid sendmethodsmtpauth value (must be: true, false)
15: Invalid sendmethodsmtptimeout value (must be numeric)
16: Invalid email address value for domainsettings_enforcedfrom

Clone a Delivery Server New in v6.0.1

POST /api/v1/deliveryserver.clone

API Usage Notes

• Authentication required: Admin API Key
• Required admin privilege: DeliveryServers
• v1 REST alias: POST /api/v1/deliveryserver.clone. Legacy access via /api.php is also supported
• Creates a new delivery server from an existing one. The new server gets the source's ConnectionParams, including the stored SMTP password, and its Domains settings, copied on the server. The password is never returned.
• The verification results are reset to false and the last-checked time is cleared, as for a newly created server. Run deliveryserver.verify on the clone.
• Not copied: email headers scoped to the source server, user group channel assignments and delivery routes.
• Fires the DeliveryServers.Create.Post plugin hook with the new server's ID, the same hook deliveryserver.create fires.

Request Body Parameters:

Parameter	Type	Required	Description
Command	String	Yes	API command: deliveryserver.clone
SessionID	String	No	Session ID obtained from login
APIKey	String	No	API key for authentication
DeliveryServerID	Integer	Yes	ID of the delivery server to copy. Must be an integer or a string of digits greater than 0. Any other value, such as true or 1.0, returns error 2
DeliveryServerName	String	No	Name of the new server. Leading and trailing whitespace is trimmed and the name is cut to 250 characters. When it is omitted or empty after trimming, the name is the source server's name followed by (Copy)

Example Request

curl -X POST https://example.com/api.php \
  -H "Content-Type: application/json" \
  -d '{
    "Command": "deliveryserver.clone",
    "SessionID": "admin-session-id",
    "DeliveryServerID": 123,
    "DeliveryServerName": "Secondary SMTP Server"
  }'

Success Response

{
  "Success": true,
  "ErrorCode": 0,
  "ErrorText": "",
  "DeliveryServerID": 124
}

Error Response

{
  "Success": false,
  "ErrorCode": [2],
  "ErrorText": ["Delivery server not found"]
}

Error Codes

0: Success
1: Missing deliveryserverid
2: Delivery server not found
3: Delivery server could not be created

Save Delivery Server Test Results

GET /api/v1/deliveryserver.testresults

API Usage Notes

• Authentication required: Admin API Key
• v1 REST alias: GET /api/v1/deliveryserver.testresults. Legacy access via /api.php is also supported
• Since v5.9.6 this command runs the real verification (a test message through the server's own SMTP credentials, then the SPF, DKIM and DMARC TXT checks and the CNAME checks on the MFROM, link-tracking and open-tracking hosts) and stores what the check found. The test_results and last_checked_at values you send are accepted for backward compatibility and ignored. Before v5.9.6 the command stored those values as sent, with no check, so any admin caller could mark a server verified (issue #2769).
• The test message is sent to the authenticated admin's email address, with the admin's name as sender name. To pick another recipient, and to receive the results in the response instead of reading them back with deliveryserver.get, call deliveryserver.verify.
• Every call sends real mail and performs six DNS lookups, so since v5.9.6 this command is rate limited the same way as deliveryserver.verify: 10 calls per 300 seconds per caller.
• In demo mode the command answers Success: true without running or storing anything.
• The recipient is always the authenticated admin's stored email address. If that address is empty or invalid the test send fails and email_delivery is stored as false; the response does not say why, so check the admin record if deliveryserver.verify reports a send failure that names the recipient.
• Parameter names are matched after lowercasing, so send them exactly as test_results and last_checked_at (with the underscores). Earlier versions of this page showed TestResults and LastCheckedAt; those lowercase to testresults / lastcheckedat, never matched the handler, and always answered ErrorCode [2, 4].

Request Body Parameters:

Parameter	Type	Required	Description
Command	String	Yes	API command: deliveryserver.testresults
SessionID	String	No	Session ID obtained from login
APIKey	String	No	API key for authentication
DeliveryServerID	Integer	Yes	ID of the delivery server to verify
test_results	Object	Yes	Accepted for backward compatibility, ignored. Any non-empty value satisfies the check (for example {"spf": false})
last_checked_at	String	Yes	Accepted for backward compatibility, ignored. The stored VerificationLastCheckedAt is the time the check ran

Example Request

curl -X POST https://example.com/api.php \
  -H "Content-Type: application/json" \
  -d '{
    "Command": "deliveryserver.testresults",
    "SessionID": "admin-session-id",
    "DeliveryServerID": 123,
    "test_results": {"spf": false},
    "last_checked_at": "2025-12-28 10:30:00"
  }'

Success Response

{
  "Success": true,
  "ErrorCode": 0,
  "ErrorText": ""
}

Error Response

{
  "Success": false,
  "ErrorCode": [3],
  "ErrorText": ["Invalid deliveryserverid"]
}

Error Codes

0: Success
1: Missing deliveryserverid
2: Missing test_results
3: Invalid deliveryserverid
4: Missing last_checked_at

Read the stored outcome back with deliveryserver.get: VerificationResults holds the seven booleans (email_delivery, spf, dkim, dmarc, sender_domain, link_domain, open_domain) and VerificationLastCheckedAt the time of the check.

Update a Delivery Server

POST /api/v1/deliveryserver.update

API Usage Notes

• Authentication required: Admin API Key
• v1 REST alias: POST /api/v1/deliveryserver.update. Legacy access via /api.php is also supported

Request Body Parameters:

Parameter	Type	Required	Description
Command	String	Yes	API command: deliveryserver.update
SessionID	String	No	Session ID obtained from login
APIKey	String	No	API key for authentication
DeliveryServerID	Integer	Yes	ID of the delivery server to update
DeliveryServerName	String	Yes	Name of the delivery server
SendMethodSMTPHost	String	Yes	SMTP server hostname or IP address
SendMethodSMTPPort	Integer	Yes	SMTP server port (e.g., 25, 587, 465)
SendMethodSMTPSecure	String	Yes	Security protocol: "false", "ssl", or "tls"
SendMethodSMTPTimeout	Integer	Yes	Connection timeout in seconds (must be numeric)
SendMethodSMTPAuth	Boolean	Yes	Whether SMTP authentication is required: true or false
SendMethodSMTPUsername	String	Conditional	SMTP username (required if SendMethodSMTPAuth is true)
SendMethodSMTPPassword	String	No	SMTP password. Changed in v6.0.1: omit it to keep the stored password. A sent value, including an empty string, replaces it
DomainSettings_LinkTracking	String	Yes	Domain for link tracking (e.g., "track.example.com")
DomainSettings_OpenTracking	String	Yes	Domain for open tracking (e.g., "open.example.com")
DomainSettings_MFrom	String	Yes	Mail From domain (e.g., "bounce.example.com")
DomainSettings_EnforcedFrom	String	No	Enforced From email address (must be valid email format)
SenderRotation_Settings	String	No	Sender rotation configuration (JSON, stored as Domains.sender_rotation_settings)
SenderInfoAsMFrom	String	No	Use sender info as MFrom: "Enabled" or "Disabled"
SenderInfoAsFrom	String	No	Use sender info as From: "Enabled" or "Disabled"
SenderRotation	String	No	Enable sender rotation: "Enabled" or "Disabled"

The stored SMTP password is kept when omitted (v6.0.1)

deliveryserver.update replaces the server's ConnectionParams and Domains as a whole. deliveryserver.get and deliveryservers.get never return smtp_password, so an integration cannot read it back and resend it. When the request omits SendMethodSMTPPassword, the stored password is kept. Before v6.0.1 an omitted password was stored as empty, which broke the server's sending.

Example Request

curl -X POST https://example.com/api.php \
  -H "Content-Type: application/json" \
  -d '{
    "Command": "deliveryserver.update",
    "SessionID": "admin-session-id",
    "DeliveryServerID": 123,
    "DeliveryServerName": "Updated SMTP Server",
    "SendMethodSMTPHost": "smtp2.example.com",
    "SendMethodSMTPPort": 587,
    "SendMethodSMTPSecure": "tls",
    "SendMethodSMTPTimeout": 30,
    "SendMethodSMTPAuth": true,
    "SendMethodSMTPUsername": "new_user",
    "SendMethodSMTPPassword": "new_password",
    "DomainSettings_LinkTracking": "track.example.com",
    "DomainSettings_OpenTracking": "open.example.com",
    "DomainSettings_MFrom": "bounce.example.com",
    "SenderRotation": "Enabled"
  }'

Success Response

{
  "Success": true,
  "ErrorCode": 0,
  "ErrorText": "",
  "DeliveryServerID": 123
}

Error Response

{
  "Success": false,
  "ErrorCode": [17],
  "ErrorText": ["Delivery server not found"]
}

Error Codes

0: Success
1: Missing deliveryservername
2: Missing sendmethodsmtphost
3: Missing sendmethodsmtpport
4: Missing sendmethodsmtpsecure
5: Missing sendmethodsmtptimeout
6: Missing sendmethodsmtpauth
7: Missing sendmethodsmtpusername
8: Missing sendmethodsmtppassword
9: Missing domainsettings_linktracking
10: Missing domainsettings_opentracking
11: Missing domainsettings_mfrom
12: Missing domainsettings_enforcedfrom
13: Invalid sendmethodsmtpsecure value (must be: false, ssl, tls)
14: Invalid sendmethodsmtpauth value (must be: true, false)
15: Invalid sendmethodsmtptimeout value (must be numeric)
16: Invalid email address value for domainsettings_enforcedfrom
17: Delivery server not found

Delete Delivery Servers

POST /api/v1/deliveryservers.delete

API Usage Notes

• Authentication required: Admin API Key
• v1 REST alias: POST /api/v1/deliveryservers.delete. Legacy access via /api.php is also supported
• Deleting a server resets every user group whose TargetDeliveryServerID_Marketing, TargetDeliveryServerID_Transactional or TargetDeliveryServerID_AutoResponder option pointed at it back to 0 (system default), after invalidating the Email Gateway per-user cache for those groups. UserGroupsReset in the response lists the user group ids that were updated.

Request Body Parameters:

Parameter	Type	Required	Description
Command	String	Yes	API command: deliveryservers.delete
SessionID	String	No	Session ID obtained from login
APIKey	String	No	API key for authentication
DeliveryServerID	String	Yes	Comma-separated list of delivery server IDs to delete (e.g., "123,456,789")

Example Request

curl -X POST https://example.com/api.php \
  -H "Content-Type: application/json" \
  -d '{
    "Command": "deliveryservers.delete",
    "SessionID": "admin-session-id",
    "DeliveryServerID": "123,456"
  }'

Success Response

{
  "Success": true,
  "ErrorCode": 0,
  "UserGroupsReset": [2, 5]
}

Error Response

{
  "Success": false,
  "ErrorCode": [1]
}

Error Codes

0: Success
1: Missing deliveryserverid

Get Delivery Servers

GET /api/v1/deliveryservers.get

API Usage Notes

• Authentication required: Admin API Key
• v1 REST alias: GET /api/v1/deliveryservers.get. Legacy access via /api.php is also supported
• The filter, ordering and paging parameters are all optional. The defaults reproduce the previous response: every server, Name ASC, unpaged.

The SMTP password is not returned (changed in v6.0.1)

ConnectionParams.smtp_password is no longer returned. Each server carries HasSMTPPassword instead, which is true when a password is stored, and DeliveryServerID is an integer. ConnectionParams carries only smtp_host, smtp_port, smtp_secure, smtp_timeout, smtp_auth and smtp_username, and any other stored key is withheld. Each server in the list is the same object deliveryserver.get returns for it. To change the password, use deliveryserver.update, which keeps the stored password when it is omitted.

Request Body Parameters:

Parameter	Type	Required	Description
Command	String	Yes	API command: deliveryservers.get
SessionID	String	No	Session ID obtained from login
APIKey	String	No	API key for authentication
DeliveryServerID	Integer	No	Return only this server (still keyed by id)
OrderField	String	No	Name (default), DeliveryServerID, VerificationLastCheckedAt
OrderType	String	No	ASC (default) or DESC
RecordsFrom	Integer	No	Offset (default 0)
RecordsPerRequest	Integer	No	Page size (default 0 = all, max 1000)

Example Request

curl -X POST https://example.com/api.php \
  -H "Content-Type: application/json" \
  -d '{
    "Command": "deliveryservers.get",
    "SessionID": "admin-session-id"
  }'

Success Response

{
  "Success": true,
  "ErrorCode": 0,
  "TotalDeliveryServerCount": 1,
  "RecordsFrom": 0,
  "RecordsPerRequest": 0,
  "OrderField": "Name",
  "OrderType": "ASC",
  "DeliveryServers": {
    "123": {
      "DeliveryServerID": 123,
      "Name": "Primary SMTP Server",
      "ConnectionParams": {
        "smtp_host": "smtp.example.com",
        "smtp_port": 587,
        "smtp_secure": "tls",
        "smtp_timeout": 30,
        "smtp_auth": true,
        "smtp_username": "smtp_user"
      },
      "HasSMTPPassword": true,
      "Domains": {
        "link_tracking": "track.example.com",
        "open_tracking": "open.example.com",
        "mfrom_domain": "bounce.example.com",
        "enforced_from": "noreply@example.com",
        "senderinfo_as_mfrom": false,
        "senderinfo_as_from": false
      },
      "VerificationResults": {
        "email_delivery": true,
        "spf": true,
        "dkim": true,
        "dmarc": true,
        "sender_domain": true,
        "link_domain": true,
        "open_domain": true
      },
      "VerificationLastCheckedAt": "2025-12-28 10:30:00",
      "UserGroupAssignments": [
        {
          "UserGroupID": "1",
          "GroupName": "Default User Group",
          "Channels": ["Marketing", "Transactional"]
        },
        {
          "UserGroupID": "5",
          "GroupName": "Enterprise Users",
          "Channels": ["AutoResponder"]
        }
      ],
      "IsAllocated": true
    }
  }
}

Error Response

{
  "Success": false,
  "ErrorCode": 2
}

Error Codes

0: Success
2: No delivery servers found

Response Field Reference:

Field	Type	Description
TotalDeliveryServerCount	Integer	Real total number of servers matching the filter, independent of paging
RecordsFrom	Integer	Offset in effect
RecordsPerRequest	Integer	Page size in effect (0 = all)
OrderField	String	Ordering field in effect
OrderType	String	Ordering direction in effect
DeliveryServers	Object	Map of delivery servers keyed by DeliveryServerID
DeliveryServerID	Integer	Unique identifier for the delivery server (a string before v6.0.1)
Name	String	Display name of the delivery server
ConnectionParams	Object	SMTP connection configuration: smtp_host, smtp_port, smtp_secure, smtp_timeout, smtp_auth and smtp_username. smtp_password is not returned (v6.0.1)
HasSMTPPassword	Boolean	true when the server stores an SMTP password (v6.0.1)
Domains	Object	Domain settings for tracking and sender identity
VerificationResults	Object	DNS and delivery verification test results
VerificationLastCheckedAt	String	Timestamp of last verification check
UserGroupAssignments	Array	List of user groups assigned to this delivery server. Each entry contains UserGroupID, GroupName, and Channels (array of channel names: Marketing, Transactional, AutoResponder)
IsAllocated	Boolean	Whether the delivery server is assigned to at least one user group channel

Get a Delivery Server

GET /api/v1/deliveryserver.get

API Usage Notes

• Authentication required: Admin API Key
• Required admin privilege: DeliveryServers
• v1 REST alias: GET /api/v1/deliveryserver.get. Legacy access via /api.php is also supported
• ConnectionParams.smtp_password is never returned; HasSMTPPassword says whether one is stored. Changed in v6.0.1 ConnectionParams carries only smtp_host, smtp_port, smtp_secure, smtp_timeout, smtp_auth and smtp_username, and only those the server has stored. Any other stored key is left out. Credential keys nested inside a returned value (such as smtp_password, ConnectionParams, Password or APIKey) are also removed, and the same removal applies to Domains and VerificationResults. Since v6.0.1, deliveryserver.update keeps the stored password when SendMethodSMTPPassword is omitted, so a client editing a server does not need to hold it.
• Since v6.0.1, deliveryservers.get returns the same object for each server.
• UserGroupAssignments / IsAllocated are the same reverse map deliveryservers.get computes from every user group's TargetDeliveryServerID_* options.

Request Body Parameters:

Parameter	Type	Required	Description
Command	String	Yes	API command: deliveryserver.get
SessionID	String	No	Session ID obtained from login
APIKey	String	No	API key for authentication
DeliveryServerID	Integer	Yes	ID of the delivery server

Example Request

curl -X POST https://example.com/api.php \
  -H "Content-Type: application/json" \
  -d '{
    "Command": "deliveryserver.get",
    "AdminAPIKey": "your-admin-api-key",
    "DeliveryServerID": 123
  }'

Success Response

{
  "Success": true,
  "ErrorCode": 0,
  "ErrorText": "",
  "DeliveryServer": {
    "DeliveryServerID": 123,
    "Name": "Primary SMTP Server",
    "ConnectionParams": {
      "smtp_host": "smtp.example.com",
      "smtp_port": "587",
      "smtp_secure": "tls",
      "smtp_timeout": "30",
      "smtp_auth": true,
      "smtp_username": "smtp_user"
    },
    "HasSMTPPassword": true,
    "Domains": {
      "link_tracking": "track.example.com",
      "open_tracking": "open.example.com",
      "mfrom_domain": "bounce.example.com",
      "enforced_from": "",
      "sender_rotation_settings": "",
      "senderinfo_as_mfrom": false,
      "senderinfo_as_from": false,
      "sender_rotation": false
    },
    "VerificationResults": {
      "email_delivery": true,
      "spf": true,
      "dkim": true,
      "dmarc": false,
      "sender_domain": true,
      "link_domain": true,
      "open_domain": true
    },
    "VerificationLastCheckedAt": "2026-09-04 10:12:33",
    "UserGroupAssignments": [
      {"UserGroupID": "2", "GroupName": "Agencies", "Channels": ["Marketing", "Transactional"]}
    ],
    "IsAllocated": true
  }
}

Error Response

{
  "Success": false,
  "ErrorCode": [2],
  "ErrorText": ["Delivery server not found"]
}

Error Codes

0: Success
1: Missing DeliveryServerID
2: Delivery server not found

Verify a Delivery Server

POST /api/v1/deliveryserver.verify

API Usage Notes

• Authentication required: Admin API Key
• Required admin privilege: DeliveryServers
• Rate limited: 10 calls per 300 seconds. Every call sends a real test message through the server's SMTP credentials and performs six DNS lookups.
• v1 REST alias: POST /api/v1/deliveryserver.verify. Legacy access via /api.php is also supported
• Not available when DEMO_MODE_ENABLED is on (error 4).
• Runs the same verification as the admin screen's "Test" button (DeliveryServers::Verify): a test send, then SPF, DKIM (DNS_DKIM_KEY._domainkey.<mfrom>) and DMARC TXT checks on the MFROM domain, and CNAME checks on the MFROM, link-tracking and open-tracking hosts against DNS_SENDER_DOMAIN, DNS_LINK_TRACKER and DNS_OPEN_TRACKER. The seven booleans are persisted to VerificationResults together with VerificationLastCheckedAt, exactly as the screen does.
• The test message goes to the authenticated admin's email address unless To is given.
• deliveryserver.testresults runs the same verification since v5.9.6 but answers only the Success envelope; prefer this command for a UI, it returns the results and the per-check messages.

Request Body Parameters:

Parameter	Type	Required	Description
Command	String	Yes	API command: deliveryserver.verify
SessionID	String	No	Session ID obtained from login
APIKey	String	No	API key for authentication
DeliveryServerID	Integer	Yes	ID of the delivery server
To	String	No	Recipient of the test message (defaults to the admin's email address)

Example Request

curl -X POST https://example.com/api.php \
  -H "Content-Type: application/json" \
  -d '{
    "Command": "deliveryserver.verify",
    "AdminAPIKey": "your-admin-api-key",
    "DeliveryServerID": 123,
    "To": "postmaster@example.com"
  }'

Success Response

{
  "Success": true,
  "ErrorCode": 0,
  "ErrorText": "",
  "DeliveryServerID": 123,
  "AllPassed": false,
  "VerificationResults": {
    "email_delivery": true,
    "spf": true,
    "dkim": true,
    "dmarc": false,
    "sender_domain": true,
    "link_domain": true,
    "open_domain": true
  },
  "Messages": {
    "email_delivery": "",
    "spf": "",
    "dkim": "",
    "dmarc": "DMARC record not found",
    "sender_domain": "",
    "link_domain": "",
    "open_domain": ""
  },
  "VerificationLastCheckedAt": "2026-09-04 10:12:33",
  "TestEmailSentTo": "postmaster@example.com"
}

Error Response

{
  "Success": false,
  "ErrorCode": [2],
  "ErrorText": ["Delivery server not found"]
}

Error Codes

0: Success
1: Missing DeliveryServerID
2: Delivery server not found
3: Invalid To email address
4: Not available in demo mode