[Dovecot] Dovecot and Outlook Express "plaintext authentication not allowed..."

[D Chen]

Hi Charles,

Thanks for the response.

Per your suggestion, in Outlook Express I changed to use SSL on port 993 for IMAP, and port 465 for SMTP, the creation of the new account succeeded without error!  However, when tried to send to my yahoo mail or gmail acct,  got the following error: (apparently failed to send!)

"The message could not be sent because one of the recipients was rejected by the server.  The
rejected email address was 'dchenusa at yahoo.com.'  Subject: 'test out to yahoo mail'
Account:'dchen192.168.20.100'
Server: 192.168.20.100
Protocol: SMTP, server response: 554 5.7.1
<unknown[192.168.20.51]>: client host rejected access denied, port: 465,
Secured [SSL]: Yes, server Error: 554, Error number: 0x800CCC79"

PS. in the same client PC, using Thunderbird client, IMAP and SMTP configured with either with SSL or without SSL, both outgoing mails were sent successfully!

Any thought?

Thx again,

Dennis


________________________________
 From: Charles Marcus <CMarcus at Media-Brokers.com>
To: dovecot at dovecot.org 
Sent: Tuesday, April 17, 2012 3:26 AM
Subject: Re: [Dovecot] Dovecot and Outlook Express "plaintext authentication not allowed..."
 
On 2012-04-17 5:16 AM, D Chen <dchenusa at yahoo.com> wrote:
> When tried to set up a new Outlook Express mail acct, the following error encountered:
> 
>       Your IMAP server wishes to alert you to the following:
>       plaintext authentication not allowed without SSL/TLS, but your client did it anyway.

Ummm... hello? McFly? ;)

You need to configure SSL on Outlook Express (why on gods green earth you are using that is beyond me), as the error plainly says. Until you do this it doesn't matter what you enter for a username/password.

Also, you should be using SSL on port 993, because I'm fairly certain that Outlook Express doesn't support STARTTLS on port 143.

And off topic but in the same vein, for postfix/SMTP relay you should be using the submission port (STARTTLS on port 587) for most clients, but I think Outlook Express again doesn't work with it, so you will need to use the deprecated SSL on port 465 (these two need to be enabled in postfix/master.cf - just uncomment the examples).

-- 
Best regards,

Charles