SMTP dialog errors

Servercore mail service uses the SMTP protocol. When sending mail from your server to the service mail node, the following SMTP dialog errors may occur.

550 bounced check filter	The email address of one of the recipients is on the stop list. If the email specifies more than one recipient, resend it to each recipient separately. If the address is on the local stop list, you can find and remove the address from the local stop list
501 from domain not trusted	The domain from which the email is sent is not added to the allowed senders list. Make sure you have correctly connected the service for the domain
421 SMTP command timeout — closing connection	The server closed the connection because it was inactive for more than 120 seconds. To resolve the error, restart the SMTP dialog
450 ratelimit exceeded	The rate limit for sending via the resource has been exceeded — 100 emails per five minutes for all resource domains. Wait a few minutes and retry sending