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Input The Reason why Fail2Ban is always blocking you might be the mail app on your phone

herrMartin

New Pleskian
Server operating system version
CentOS Linux 7.9.2009 (Core)
Plesk version and microupdate number
Plesk Obsidian Version 18.0.45
If you are blocked from your own server by Fail2Ban, you should check whether the Gmail app is running on the phone and whether IMAP/POP3 accounts are also configured there, which are collected. There may be old auth data entered and that locks you out.
You may have entered this account in the web interface, the web version does not give an error message etc.. and Important, with the web version Gmail servers directly connecting to the mail server.
The app takes over the data you setup in the web interface, but the mail collections happen by the client from the phone to the mail server.


Wer von seinem eigenen Server durch Fail2Ban gesperrt wird, sollte mal schauen, ob auf dem Telefon die Gmail App läuft und dort IMAP/POP3 Konten zusätzlich noch konfiguriert sind, welche eingesammelt werden. Dort können alte Auth-Daten eingetragen sein und das sperrt euch aus. Ggf. habt Ihr diesen Account in der Weboberfläche eingetragen, die Webversion gibt keine Fehlermeldung etc. Die App übernimmt Daten, fragt diese aber selbst von Eurer IP ab
 
The same is good advice for email apps and clients in general. It also applies to all kinds of operating system. Wrong email credentials are the most frequent cause for Fail2Ban bans.
 
This has driven me nuts for one year. I searched my home for all devices which can do email. Removed every trace of an email client and nothing and yesterday when I was in bed I remembered that you can configure Gmail to collects mails from other servers, and then I looked into the app on my phone. A big WTF.
I
 
Yeah, that can cause headaches. A good point to start is also looking at /var/log/maillog (mail.log on Debian/Ubuntu) and at times with "auth" errors in the middle of the night. As mostly desktop devices are turned off, only the phones are still connecting.
 
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