Mailing List Message #106929
From: Christian F Buser <>
Subject: Re: 550 server without authentication error
Date: Wed, 15 Aug 2018 14:50:33 +0200
To: CommuniGate Pro Discussions <>
X-Mailer: GyazMail version 1.5.19
Hello DUDLEY Paul On Wed, 15 Aug 2018 04:32:04 +0000, you wrote:
> At this point in time this is the only external email domain that we
> are sending to which is reporting this problem.
> Are there any settings I can check on our CommuniGate Pro server?

You asked the same question 2 weeks ago. And then, you also noted:

> We have the outgoing SMTP setting set to send directly to the recipient.

which seems to be the cause of your problem. Why can't you just use your provider's SMTP server (and authenticate with them)? Some (or probably many) SMTP servers don't like to receive messages from dynamically assigned IP addresses without authentification.

Christian F. Buser, Hohle Gasse 6, CH-5507 Mellingen (Switzerland)      
Hilfe fuer Strassenkinder in Ghana:
Subscribe (FEED) Subscribe (DIGEST) Subscribe (INDEX) Unsubscribe Mail to Listmaster