Errors in SMTP dialog
The Selectel email service uses the SMTP protocol. The following SMTP dialog errors may occur when sending mail from your server to the service's mail host.
Stop list
The recipient's email address goes into your local stop list if one of the previous sends to it received status:
unsubscribe
— the recipient has unsubscribed from the mailing list;fbl
— the recipient complained about spam;failed
— the email address could not be sent to.
Emails to email addresses from the stop list are not sent, the SMTP dialog returns the error 550 bounced check filter
.
If you have specified multiple recipients in an email and at least one of the email addresses is on the stop list, the email will not be sent to any of them. To determine which address is on the stop list, send the email separately to each of the recipients.
If you believe an address has been placed on the stop list by mistake, you can remove it from the stop list using API method.