Gmail and POP3

[Yannick SIEGLER]

Hi everyone, I'm new to this ML.


I have some issue with GMail import settings...

I run a dovecot server (2.3.4.1) on Debian10 and I try to connect to my 
accounts from GMail.


It's work fine from thunderbird in pop3,pop3s, imap, imaps... Submission 
work too...

But it won't work on GMail except if I set ssl=yes and 
disable_plaintext_auth = no...

Then GMail connect without SSL or TLS... And in plaintext.... Very 
unsecure...


I can send mail with submission from GMail and ssl=require, that's ok.


If I try to connect with SSL activated I've got : pop3-login: 
Disconnected: Too many bad commands

And If I try to connect on port 995 with SSL GMail say that I have some 
SSL error, and the log says :

auth: Debug: auth client connected (pid=21831)
pop3-login: Debug: SSL: where=0x10, ret=1: before SSL initialization
pop3-login: Debug: SSL: where=0x2001, ret=1: before SSL initialization
pop3-login: Debug: SSL: where=0x2002, ret=-1: before SSL initialization
pop3-login: Debug: SSL: where=0x2001, ret=1: before SSL initialization
pop3-login: Debug: SSL: where=0x2001, ret=1: SSLv3/TLS read client hello
pop3-login: Debug: SSL: where=0x2001, ret=1: SSLv3/TLS write server hello
pop3-login: Debug: SSL: where=0x2001, ret=1: SSLv3/TLS write change 
cipher spec
pop3-login: Debug: SSL: where=0x2001, ret=1: TLSv1.3 write encrypted 
extensions
pop3-login: Debug: SSL: where=0x2001, ret=1: SSLv3/TLS write certificate
pop3-login: Debug: SSL: where=0x2001, ret=1: TLSv1.3 write server 
certificate verify
pop3-login: Debug: SSL: where=0x2001, ret=1: SSLv3/TLS write finished
pop3-login: Debug: SSL: where=0x2001, ret=1: TLSv1.3 early data
pop3-login: Debug: SSL: where=0x2002, ret=-1: TLSv1.3 early data
pop3-login: Debug: SSL: where=0x2002, ret=-1: TLSv1.3 early data
pop3-login: Debug: SSL: where=0x2002, ret=-1: TLSv1.3 early data
pop3-login: Debug: SSL: where=0x2002, ret=-1: TLSv1.3 early data
pop3-login: Debug: SSL: where=0x2001, ret=1: TLSv1.3 early data
pop3-login: Debug: SSL: where=0x2001, ret=1: SSLv3/TLS read finished
pop3-login: Debug: SSL: where=0x20, ret=1: SSLv3/TLS write session ticket
pop3-login: Debug: SSL: where=0x2001, ret=1: SSLv3/TLS write session ticket
pop3-login: Debug: SSL: where=0x2001, ret=1: SSLv3/TLS write session ticket
pop3-login: Debug: SSL: where=0x2002, ret=1: SSL negotiation finished 
successfully
pop3-login: Debug: SSL error: Connection closed

But as I say, all is working fine from Thunderbird...

For the SSL problem this is maybe because GMail doesn't like this 
configuration in debian for openssl ?

[system_default_sect]
MinProtocol = TLSv1.2
CipherString = DEFAULT at SECLEVEL=2


Maybe should I try to set

MinProtocol = None
CipherString = DEFAULT

But this make a lot of security change on my opinion...


Do someone have any tips or suggestion about my problem ?


Thx


Yannick