Issue smtp dns entry missing after domain migration

[PeterKi]

Server operating system version

Linux Ubuntu 20.04.5 LTS

Plesk version and microupdate number

Plesk Obsidian 18.0.49

I have a Linux server with Plesk Obsidian 18.0.49 and I'm running 2 domains on it.
Both domains have Let's encrypt setup and sending and receiving mails used to work properly for years.
Two days ago I did transfer one of the two domains to another hoster and now I cannot send mails from that domain anymore.
An nslookup shows that the DNS entries for mail.{mydomain1|2} are there, but the entry smtp.{mydomain2} is missing.
If I compare the DNS settings in Home > Domains : Hosting & DNS, the entries for both domains are similar and neither one of them shows an smtp.{mydomain1|2} entry.
I cannot find where the smtp.{mydomain1} DNS entry comes from.
What creates the DNS alias for smtp.{mydomain} and how can I fix the problem?

 

[Maarten.]

Hi,

You can add those entries via: Tools & Settings -> DNS Settings -> Zone Records Template

 

[PeterKi]

Thanks for pointing me there, but there is no smtp entry in the template although nslookup shows an smtp record for my other (still untouched) domain.
In the meantime I have added an smtp.{mydomain2} entry in the DNS web GUI of my new hoster, and now I can send mails from the transferred domain again.
I am still wondering though where the smtp entry for my other domain comes from.
I cannot find it neither in plesk nor on the DNS web GUI of my old hoster.
I have never added an smtp DNS alias for my mail, so I suppose that plesk has done it somewhere in the background when a mail service is setup.

 

[scsa20]

If you're using the DNS service that's within plesk, the SMTP A record should had been created from the template or, at the very least, created when the email service is turned on and should had shown in the web interface so it's weird that it didn't. You could always look at the zone's configuration directly which is located in /var/named/chroot/var/domain.tld (location might be different but that's where it's at for my centos install) and see if it might be listed in there, if so, then there's some sort of disconnect between the web interface vs actual.

 

[PeterKi]

There is no /var/named/chroot directory and there is also no domain.tld file on Ubuntu.
There is an /etc/bind directory with some files in it but they are rather old and I suppose they are not used by Plesk.
In the meantime, I found that the imap.{mydomain} record was also missing, which made my windows mail checker croak with server not found.
A difference in DNS between the migrated domain and the not migrated domain is in the name server records.
The original NS records point to my server itself while the migrated domains NS records point to the name servers of the provider.
Thus, I suppose that Plesk creates DNS aliases for IMAP and SMTP when a mail domain is created.
It is strange though, that these aliase don't show up in the zone template or in the domain DNS entries.

 

[PeterKi]

Correction: it seems that my old provider has added DNS aliases for IMAP and SMTP.
At least a dig +trace imap.{mydomain} revealed a CNAME record coming from the provider's name server.
As the provider did not only host the domain but also my vServer there could be some interaction when I did setup the Linux server with plesk.
Now that I know this, I guess, I need to manually create the CNAME records at the new provider (which only hosts the domain records but not the server), whenever I set up a mail domain on my server.

 

[PeterKi]

Having found the CNAME records for my domain, it raises 2 questions to me.
1. Should I point the NS records for my domain to my server in the DNS config of my provider?
2. If 1 is true, shouldn't then Plesk have the CNAME entrys for IMAP and SMTP in the Zone Records Template by default?

 

[scsa20]

You could point the name servers to your plesk server but you would need to first set up glue records which varies from each registrar and not all registrars supports it (most do though).

The default domain DNS templates does creates CNAME records for IMAP, SMTP, and what not

 

[PeterKi]

Hmm,
I haven't done anything to my Zone Records Template, and this is what it looks like on my server:
[TABLE] [TR] [TH][/TH] [/TR] [/TABLE] [TABLE] [TR] [TD][/TD] [TD]<domain>.[/TD] [TD][/TD] [TD]NS[/TD] [TD]ns1.<domain>.[/TD] [/TR] [TR] [TD][/TD] [TD]<domain>.[/TD] [TD][/TD] [TD]NS[/TD] [TD]ns2.<domain>.[/TD] [/TR] [TR] [TD][/TD] [TD]<domain>.[/TD] [TD][/TD] [TD]A[/TD] [TD]<ip>[/TD] [/TR] [TR] [TD][/TD] [TD]<domain>.[/TD] [TD][/TD] [TD]AAAA[/TD] [TD]<ipv6>[/TD] [/TR] [TR] [TD][/TD] [TD]<domain>.[/TD] [TD][/TD] [TD]MX[/TD] [TD]mail.<domain>.[/TD] [/TR] [TR] [TD][/TD] [TD]<domain>.[/TD] [TD][/TD] [TD]TXT[/TD] [TD]v=spf1 +a +mx +a:<hostname> -all[/TD] [/TR] [TR] [TD][/TD] [TD]_dmarc.<domain>.[/TD] [TD][/TD] [TD]TXT[/TD] [TD]v=DMARC1; p=none[/TD] [/TR] [TR] [TD][/TD] [TD]ftp.<domain>.[/TD] [TD][/TD] [TD]CNAME[/TD] [TD]<domain>.[/TD] [/TR] [TR] [TD][/TD] [TD]ipv4.<domain>.[/TD] [TD][/TD] [TD]A[/TD] [TD]<ip>[/TD] [/TR] [TR] [TD][/TD] [TD]ipv6.<domain>.[/TD] [TD][/TD] [TD]AAAA[/TD] [TD]<ipv6>[/TD] [/TR] [TR] [TD][/TD] [TD]mail.<domain>.[/TD] [TD][/TD] [TD]A[/TD] [TD]<ip>[/TD] [/TR] [TR] [TD][/TD] [TD]mail.<domain>.[/TD] [TD][/TD] [TD]AAAA[/TD] [TD]<ipv6>[/TD] [/TR] [TR] [TD][/TD] [TD]ns1.<domain>.[/TD] [TD][/TD] [TD]A[/TD] [TD]<ip>[/TD] [/TR] [TR] [TD][/TD] [TD]ns1.<domain>.[/TD] [TD][/TD] [TD]AAAA[/TD] [TD]<ipv6>[/TD] [/TR] [TR] [TD][/TD] [TD]ns2.<domain>.[/TD] [TD][/TD] [TD]A[/TD] [TD]<ip>[/TD] [/TR] [TR] [TD][/TD] [TD]ns2.<domain>.[/TD] [TD][/TD] [TD]AAAA[/TD] [TD]<ipv6>[/TD] [/TR] [TR] [TD][/TD] [TD]webmail.<domain>.[/TD] [TD][/TD] [TD]A[/TD] [TD]<ip>[/TD] [/TR] [TR] [TD][/TD] [TD]webmail.<domain>.[/TD] [TD][/TD] [TD]AAAA[/TD] [TD]<ipv6>[/TD] [/TR] [TR] [TD][/TD] [TD]www.<domain>.[/TD] [TD][/TD] [TD]CNAME[/TD] [TD]<domain>.[/TD] [/TR] [/TABLE]

 

[scsa20]

The way you have your zone layout listed on the post is kinda hard to read but here's what my zone template looks like:

    <domain>.        NS    ns1.<domain>.
    <domain>.        NS    ns2.<domain>.
    <domain>.        A    <ip>
    <domain>.        AAAA    <ipv6>
    <domain>.        MX    mail.<domain>.
    <domain>.        TXT    v=spf1 +a +mx +a:<hostname> ~all
    _dmarc.<domain>.        TXT    v=DMARC1; adkim=s; aspf=s; p=quarantine
    _domainconnect.<domain>.        TXT    domainconnect.plesk.com/host/<hostname>/port/8443
    ftp.<domain>.        CNAME    <domain>.
    ipv4.<domain>.        A    <ip>
    ipv6.<domain>.        AAAA    <ipv6>
    mail.<domain>.        A    <ip>
    mail.<domain>.        AAAA    <ipv6>
    ns1.<domain>.        A    <ip>
    ns1.<domain>.        AAAA    <ipv6>
    ns2.<domain>.        A    <ip>
    ns2.<domain>.        AAAA    <ipv6>
    webmail.<domain>.        A    <ip>
    webmail.<domain>.        AAAA    <ipv6>
    www.<domain>.        CNAME    <domain>.

Also taking a look deeper (since I haven't looked at the default template in awhile), it looks like the SMTP, IMAP, and POP DNS entries doesn't get created unless the email services is enabled on the domain so if it's not enabled the entries won't be created by default. And it won't be in the normal sense, it's more of _imaps. and what not as a SRV record for autodiscover configurations.

 

[PeterKi]

Sorry for the garbled table.
Your default table looks very much like mine, although I have enabled email services on 2 of my domains and I use them with horde as well as IMAP on thunderbird.