Migrating from Olde server to Dovecot

[Timo Sirainen]

On 04 Apr 2016, at 09:49, Hendrik Velloen <hendrik00 at gmail.com> wrote:
> 
> Hi
> 
> dsync(hendrikv at tcmvpn.co.za): Error: pop3c(196.26.136.162): AUTH PLAIN
> failed: -ERR Invalid command, try one of: USER name, PASS string, APOP name
> digest, QUIT

Dovecot tries to use AUTH PLAIN instead of the regular USER+PASS. I think you have set pop3c_master_user setting, which enables this behavior.