Auto replies are not received by external mail servers

Symptoms

• The auto reply mailbox domain has its DMARC policy set to reject

  "v=DMARC1; p=reject; pct=100"

• Auto replies sent by the local mail server are sent to spam or not delivered at all, with the following error

  550-5.7.26 Unauthenticated email from example.com is not accepted due to 550-5.7.26 domain's DMARC policy.

• Auto replies sent by external mail server are not delivered, with the following logged to plesk_debugYYYYMMDD.log

  Warning: SMTP Exception
  at Unable to call send()(SMTPClientSessionTransport::send line 114)
  at Unable to call send()(PocoMailMessage::Impl::send line 323)
  at sendMail(jdoe@example.com, jdoe2@example.com)(MessageProcessor::sendMail line 335)

• External SMTP server users can't send email

  # curl smtp://email-smtp.ap-south-1.amazonaws.com:587 -v --mail-from "XXXXXXXXXXXXX" --mail-rcpt "jdoe@example.com" --ssl -u XXXXXXXXXXXXX:*** -T input.txt -k --anyauth
  ...
  curl: (55) MAIL failed: 501

Cause

This was caused by a Plesk product issue, PPPM-12688.

Resolution

Starting from version 18.0.69, the Plesk implementation has been removed in favor of the native solutions from the mail server installed. As such, auto-replies should now be configured as follows: 

• Configure auto replies in a mail client: How to set up auto replies in Outlook

• Configure auto replies directly in MailEnable: How to configure auto responder in MailEnable

• SmarterMail users should configure them directly in the SmarterMail interface