Suddenly SMTP Authentication Failures

[jcobban]

Suddenly today I am unable to send E-mails consistently because a server along the route rejects the e-mail for lack of SMTP authentication. I have not changed any of the settings on the outbound server in YEARS. The panel I am presented with to edit those options does not correspond to the documentation on this site. Nor does the route to get to that panel. On my system (Ubuntu Linux) Account Settings is under Edit, not Tools. It would be nice if someone would either update the documentation to match the behavior or correct the behavior to match the documentation. The current settings for my ISP are port 26 and "Password transmitted insecurely". I hesitate to change them because my ISP sometimes insists upon unusual ports to frustrate hackers, and the current settings have worked for at least 6 years. Until today.

I have looked at all of the existing threads on this subject but all of them trail off without actually giving an explanation of what to do. This is to some extent understandable because SOME of my e-mails are getting through and I can see no pattern to why they sometimes go out and sometimes get blocked.

Thunderbird 45.5.1 on Ubuntu Linux 16.04.

[DanRaisch]

Menu path Tools->Account Settings is for Windows while Edit->Account Settings is for Linux. http://kb.mozillazine.org/Menu_differen ... x,_and_Mac

What is the exact text of the error message you are seeing and what do you have selected for Authentication Method for that account?

[jcobban]

An error occurred while sending mail. The mail server responded:
Please turn on SMTP Authentication in your mail client, or login to the
IMAP/POP3 server before sending your message.
kntaon1614w-lp130-01-70-50-134-78.dsl.bell.ca ([192.168.2.11])
[70.50.134.78]:49342 is not permitted to relay through this server without
authentication..

It would be nice if Thunderbird would let me copy the information from the output server menu to this post. I have Port: 26, Connection Security: None, Authentication method: Password, transmitted insecurely. Again I have had those same settings for over 6 years with no problem until yesterday. Some messages go out with no problems at all, possibly because the destination server is not as picky. Some messages will fail, wait a bit, fail, wait a bit, fail, wait a bit, fail, wait a bit, fail, wait a bit, fail, wait a bit, succeed. There is NOTHING different between the requests that fail and the one that succeeds except the exact time that the messages were sent. I am concerned that some of the recipients are getting the earlier messages and therefore are being bombarded by messages, but I have to keep trying to send the message until everybody gets it.

I don't know of any way to show you the menu that I am being presented with on my system because it does not correspond with the documentation on this site.

[DanRaisch]

Moving to Thunderbird Support.

That error message suggests it's not a server somewhere along the line but the specific SMTP server of your provider to which Thunderbird is handing off the messages. The text refers to turning on SMTP authentication but your reported settings include no connection security and a password submitted in the clear.

A frequent cause of such errors in system that have been stable for some time is a change on the server side, introduced by the provider with no prior notice to users. Have you confirmed with your provider that the reported settings are still valid for their outgoing server?

[shapbrown]

Just curious about this SMTP Authentication: I too as of the last update from Thunderbird can not send out messages. I get a message that suggests that I make sure that authentication is set on Normal Password as it will not accept encrypted passwords. It is and has always been set on Normal. I've reset it to Normal. I tried resetting it to No authentication. neither seemed to work.
I have spend time with my provider help services and they found all is OK on their side but not perhaps being compatible with new Thunderbird changes.
My provider is cox cable in Prov. RI. Anyone else having this problem - or have you found a fix for it?

[DanRaisch]

shapbrown, please see this post in regard to problems sending through Cox's SMTP servers -- http://forums.mozillazine.org/viewtopic ... #p14725649

[shapbrown]

Dan Thank You - helps to know I'm not alone...... when I talked to Level II the person he was very patience with me and did say (in an indirect way) that Cox was working toward some updating procedures that hopefully will resolve this incompatibility issue.. it's my business so I hope a fix is possible and soon.
I'm not that technically skilled but One suggestion I was given was to go back to a previous version of Thunderbird... but now I don't think that will help. Thank You again for the assist in understanding.

[tanstaafl]

http://www.cox.com/residential/support/ ... 0000000000} claims that you should use port 587 with TLS enabled for the SMTP server. That article was last updated Thu, 15 Sep 2016.

I suggest you configure connection security:SSL/TLS, port:587 and authentication method:normal password in the server settings. That's a very common configuration. You are using port 26, which normally doesn't support a secure connection. Most email providers nowadays don't support sending encrypted passwords because they send everything over a secure connection using TLS instead.

[DanRaisch]

You're welcome.