Question How to change Outgoing SMTP IP for all domains

[AK_learner]

Server operating system version

AlmaLinux 8.10

Plesk version and microupdate number

18.0.76 #5

Dear Pleskians, @IgorG & @Sebahat.hadzhi,

How to change Outgoing SMTP IP for all domains?

Because if I change it via the Plesk > Server-wide mail settings > Settings > Outgoing mail mode > Send from the specified IP addresses, it causes the websites IPs to also get changed simultaneously.

How to ONLY change the Outgoing SMTP IP, without causing the websites IPs to be changed?

 

[Sebahat.hadzhi]

Hi, @AK_learner . That change should not affect DNS records other than MX record (corresponding A record, typically mail.example.com). This is expected behavior to ensure the SPF values match. Changing the smtp_bind_address in /etc/postfix/main.cf directly without updating the MX records will make SPF checks fail because the IP addresses won’t match.

In case other records are updated in your case, kindly provide a screenshot of the current DNS configuration of the domain and if there are any specific steps to reproduce the issue other than changing the Outgoing mail mode to "Send from the specified IP addresses".

 

[Sebahat.hadzhi]

P.s. I am assuming that you might have the MX record pointed to the main A record of your domain, which would explain why the issue occurs on your end. If that's the case you just need to create an additional A record for a subdomain like mail.example.com and point your MX to it instead.

 

[AK_learner]

@Sebahat.hadzhi,

Thank you for getting back to me.

I would say, the second assumption of yours is correct: MX records are pointed to domain A records.

I believe the article should be updated, as I would assume many others would have also faced the same issue, as did one person who commented on that article 2 years ago and still there is no response to his query.

Also, can you provide any CLI way to change the MX records for all domains (including Serial key update of DNS zone), if they are pointing to the domain name?
i.e. Domain.com MX Priority Domain.com
instead of Domain.com MX Priority mail.domain.com?

As I have 1000s of domains and updating each one would be very time consuming.