Documentation: Testing guide, simple with external tools

[ThomDietrich]

Hey all,
My private mail server had one or the other issue over the years. The server ended up in a blacklist, the SSL certificate was not renewed, SPDIF was not or wrongly configured, etc....
Mail is a complex issue and it is not a simple task to maintain a flawless system while the environment changes from time to time.
On top of all it is not easy to check every aspect.

Yes, a fully automated checking routine would be amazing. Yes that would take some time and constant improvement to be useful.

---

I propose to collect a list of external services and simple instructions to check the different aspects of a mailcow setup. This list in documentation will help every user right away. It might furthermore spark ideas how to incrementally implement self-tests in mailcow, to replace the need for such a list eventually.

Example:

1. Check that your server can be reached and works properly: https://mxtoolbox.com/diagnostic.aspx
   The result should look similar to this:

   

2. Check that your server is not on any major blacklist ...

3. Check SSL ...

4. ...

Next steps

Is something like this already available?

I propose to collect a list of web services you guys use to check basic functionality of your mailcow systems and would suggest to be rather over-exhaustive than selecting the one tool that does not catch (PTR or any other random aspect). Just drop everything in the comments below and let's start a discussion where and in which form we want provide this list.

Any further thoughts?

[ThomDietrich]

• SMTP for IPv4 and IPv6 https://network-tools.webwiz.net/email-test.htm

• A discrete selection of tools from https://mxtoolbox.com/

• Connection and SSL details: https://www.checktls.com/TestReceiver

• Comprehensive vulnerabilities and certificate check. Including DANE: https://de.ssl-tools.net/mailservers

• Reverse DNS (PTR) check: https://www.debouncer.com/reverse-dns-check

• https://en.internet.nl/mail

• https://dnsblcheck.de

• https://domain.opendns.com/mailcow.email

[djdomi]

i belive he requests that it should be included into mailcow

[ThomDietrich]

No he is not, also it's me both times ;)

[ThomDietrich]

So far I did not find any tool to test autoconfig capability (and its various forms)

[ThomDietrich]

No interest? I hoped to collect more resources before writing the article

[andryyy]

• Test DANE https://dane.sys4.de/

[shiz0]

Pretty detailed DNS test: https://intodns.com/
For a while I had a paid account at unlocktheinbox.com. Neat thing was, you could send them an email and they would send back a detailed report. Similiar (partly free services) are:
https://www.sparkpost.com/email-tools/authentication-checker/
https://www.mail-tester.com/
I had another one, but I can't remember right now, sorry.

A pretty simple, but also effective test, is sending an email to a gmail address you may have and then viewing the source. SPF/DMARC/DKIM pass/fails are listed there as well.

Some tools i consider useful not so much for immediate testing, but for monitoring:
Sends you DMARC reports, free is it's very basic form: https://dmarc.postmarkapp.com/
Outlook Sendersupport let's you view statuses of your sending IPs: https://sendersupport.olc.protection.outlook.com/snds/
Smiliar from google: https://postmaster.google.com/
The last one may only be really useful if there's quite some amount of daily mail sent to them. For Outlook you can at least view your IP's status, even if you are a "low volume" sender.

[ThomDietrich]

Thanks both!!
Will start with a PR in ... soon (better not promise deadlines atm ^^)

[ThomDietrich]

[moved to the top]

[ThomDietrich]

Added further links to the list above

[stale]

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[ThomDietrich]

Hey Stalebot, please do not close yet. Thanks.