Forwarded to devs Changing IP of "Outgoing mail mode" (Postfix) to a specific IP will result in Web IP changing also

[PiyaphanI]

TITLE:

Changing IP of "Outgoing mail mode" (Postfix) to a specific IP will result in Web IP changing also​

PRODUCT, VERSION, OPERATING SYSTEM, ARCHITECTURE:

Plesk Onyx 17.5.3 Update #38
CentOS 6.9 64bit​

PROBLEM DESCRIPTION:

Changing IP of "Outgoing mail mode" (Postfix) to a specific IP will result in Web IP changing also​

STEPS TO REPRODUCE:

1. Add a new IP
Tools & Settings > IP Addresses

2. Change IP of "Outgoing mail mode" to new IP
Tools & Settings > Mail Server Settings > Switch an option of "Outgoing mail mode" to "Send from the specified IP addresses" + select new IP (after submitted it will take some time to finish)

3. Go to "DNS Settings" page of any domain and you will see IP of A record of "domain.com" has changed to above IP. Pinging and nslookup will show that IP is really changed. However, this will not be a problem if I can access website as usual BUT all website will show Server Default Page/CentOS Apache2 Test Page and some site worst as inaccessible. It seems Apache/NGINX configuration does not changed.

I tried to remove newly added IP but Plesk says "Unable to remove an IP address: The IP address is already used for hosting" (But I select it to use with Outgoing Mail, didn't touch with Hosting Settings)

All above problems will solve after Switch an option of "Outgoing mail mode" back to "Send from domain IP addresses". (DNS reverts to original IP but website needed few hours for DNS Cache expiring. IP can be removed without error about Hosting.)

Tested it three times, same results.​

ACTUAL RESULT:

IP of website changed unexpected.​

EXPECTED RESULT:

Website's IP should not effected by changing of Outgoing mail IP.​

ANY ADDITIONAL INFORMATION:

​

YOUR EXPECTATIONS FROM PLESK SERVICE TEAM:

Help with sorting out​

 

[IgorG]

Reply from Plesk developer:

This is not expected Plesk behavior and I cannot reproduce it. Changing Outgoing mail mode to explicit IP does affect the DNS settings, but it shouldn't be A record of "domain.com". It should be A record of "mail.domain.com". Probably customer's MX record has "<domain>." value instead of "mail.<domain>." and if this happens to all domains, it might be the problem with DNS template.
More information is required for further investigation.
Regarding misleading error on removing IP address (saying that IP address is used for hosting though it is used for mail) there is a reported issue PPPM-7984

 

[PiyaphanI]

Probably customer's MX record has "<domain>." value instead of "mail.<domain>."

Yes. you are correct.

 

[PiyaphanI]

IgorG, why changing of Outgoing mail mode does affect to A record of MX?
I understood that MX is used for Incoming only?

 

[IgorG]

Fixed in Plesk 18.0.35:

Improved a confusing error message. When users try to remove an IP address used by the mail server, Plesk no longer incorrectly notifies that the IP address is used for hosting. (PPPM-7984)