Cannot access email account from my cell phone and desktop Thunderbird

OK, after validating the domain SolarGeo.net I have no problem the site via browsers. However, while the website is accessible, there is an email problem: could not set up an email account on my phone and on my computer (for my Linux Mint desktop I use Thunderbird).

The phone gives me this error: “Couldn’t open connection to server”

As for the desktop, it gives me this error - see pic:

This is actually an old problem, starting from the first time I tested Vesta, having problem connecting the mail server now and then, some time I found that my IP was present at the Managed Banned IP’s section - removing my IP did help sometime but not all the time. I even tried whitelisting my IP in the firewall but that does not appear to help.

Anyone knows the problem? Now I cannot receive any site email at Thunderbird client - this is a major problem!

Check with iptables if your ip is filtered , from the description this is most likely the case

iptables -n -L

you could also temporary stop fail2ban if your IP gets blocked until you find out the cause.

Yes, stopping fail2ban works in allowing me to access all site email accounts from Thunderbird.

Not knowing how to find the cause of the problem, I simply edit this file:

nano /etc/fail2ban/jail.conf

Then find the line ignoreip = and add my ip there.

It works for me but may not work for my clients whose IPs have not been added to the config file.

fail2ban will block ip’s only after multiple failed auths, so there is no point in adding clients to the ignoreip

What you say @Lupu is correct. Although I had some issues in the past with older Outlook versions & Windows OS, that for some unknown reason would trigger fail2ban. The funny thing is that Outlook configuration was intact and just by lifting the ban, it would work again for some days, until it happened again.

I those rare cases I had to add the IPs to the ignoreip setting.

OK, after adding my IP to the ignoreip setting, I still have one email account that I cannot download email messages from. After checking and comparing with other email accounts on my Thurderbird, I find one difference, that is the port number for incoming email server, the working one is 110, instead of the suggested 143 for STARTTLS secured connections.