Knowledge Base

Auto replies are not received by external mail servers

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([email protected], [email protected])(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 "[email protected]" --ssl -u XXXXXXXXXXXXX:*** -T input.txt -k --anyauth
...
curl: (55) MAIL failed: 501

Plesk product issue PPPM-12688.

Warning: Using a mail client is the only solution that works 100% of the time.

There are 3 possible workarounds for this issue.

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
Edit the domain's DMARC record, changing its policy to ignore DMARC errors:

"v=DMARC1; p=none"

Note: This method won't help with mail relay cases; auto replies may still be sent to spam.