Create whosts.pl

[DarkowskiM]

Add autoconfig for whosts.pl - Polish email hosting provider.
IMAP: imap.whosts.pl:993 SSL
SMTP: smtp.whosts.pl:587 STARTTLS
POP3: imap.whosts.pl:995 SSL

[DarkowskiM]

Hi, could a maintainer please approve the workflow so the validation can run? This is a new ISP entry for whosts.pl - a Polish email hosting provider. Thank you!"

[jtracey]

The file should have a .xml extension.

[DarkowskiM]

Thank you! I've renamed the file to whosts.pl.xml

[jtracey]

Thanks! It looks like the server may support TLS for SMTP on port 465 though. Can you confirm?

[DarkowskiM]

Yes, the server supports TLS for SMTP on port 465 as well. I can add it to the configuration if needed.

[DarkowskiM]

I've updated the file to include a separate POP3 hostname (pop3.whosts.pl) and added SMTP SSL on port 465 as requested. Both ports 587 (STARTTLS) and 465 (SSL) are now included.

[babolivier]

Thanks for this PR! Maybe a long shot, but are you involved with whosts.pl, or do you have an existing relationship with them? We typically prefer that ISPs host their own autoconfig files for a range of reasons (documented here), so I'm wondering if that route has already been attempted.

[DarkowskiM]

Hi! Yes, I am the administrator of whosts.pl. The autoconfig service is already hosted directly on our server at autoconfig.whosts.pl and autodiscover.whosts.pl. The service is fully operational and serving configuration for all domains hosted on our platform. I submitted this PR to ensure Thunderbird can also find the configuration through the ISPDB for domains that may not have the autoconfig DNS records set up yet.

[babolivier]

Great, thanks for the info!

I'm not entirely make sure an ISPDB entry makes sense in this case. If a domain doesn't have the DNS entry set up, Thunderbird also uses the value of its MX record to perform an autoconfig lookup, as described on this page. In other words, if alice.com doesn't have an autoconfig. subdomain but has an MX record that points to mx.bob.com., and if autoconfig.bob.com exists and serves an autoconfig file, Thunderbird should use that file.

For a real life example, Fastmail ask their customers to set a couple of MX records pointing to inX-smtp.messagingengine.com., and serve an autoconfig file at http://autoconfig.messagingengine.com/mail/config-v1.1.xml so that customers aren't required to set up such records.

Would this be acceptable in your case?

[DarkowskiM]

Thank you for the tip! I've now set up autoconfig.mail.whosts.pl so Thunderbird can find the configuration via MX lookup for all domains with MX pointing to mail.whosts.pl. This works exactly like the Fastmail example you mentioned. I also have autoconfig CNAME records for domains with external MX servers. Given this setup, do you think the ISPDB entry is still needed or should I close this PR?

[babolivier]

I've now set up autoconfig.mail.whosts.pl so Thunderbird can find the configuration via MX lookup for all domains with MX pointing to mail.whosts.pl

As described on that page, the domain used by Thunderbird stops at the second level, so if the value of the MX is mail.whosts.pl then Thunderbird will query autoconfig.whosts.pl. It also looks like there's already a file there (sorry for not thinking to check earlier!), so I think you should already be sorted with just this one.

As a test, I configured a temporary subdomain on one of my domain with an MX record pointing at mail.whosts.pl and no autoconfig. record, and it seems like Thunderbird successfully manages to find its configuration at autoconfig.whosts.pl:

Screencast.From.2026-06-05.16-38-28.mp4

With this in place, I don't think there's a need for this PR, so I'll close it. If you happen to need further help with autoconfig and/or ISPDB in the future, feel free to ask in our mailing lists: https://thunderbird.topicbox.com/groups/autoconfig 🙂

[DarkowskiM]

Thank you so much for testing this and for the detailed explanation! Great to know it works. I appreciate your help and patience with this PR.

[babolivier]

No worries! Thanks for your patience with this as well :)