> On Jul 8, 2016, at 9:15 PM, Wietse Venema <wie...@porcupine.org> wrote: > > Your SASL library cannot authenticate with PLAIN or LOGIN.
Another possibility is that it supports and prefers XOAUTH2, but lacks
the necessary credentials or configuration to do so. In that case filtering
out that mechanism might resolve the problem. It could be that the server
side has only recently enabled that mechanism.
--
Viktor.
