RML_Seattle said

In the image, the email address "roseanneMST19@gmail.com" is an alias.

I can't tell if the image uploaded. Here is the image. Apologies if it's a duplicate. Thanks.

what server responded? If you are sending mail using a gmail account it should be going through the gmail servers.

I personally just fail to understand this alias stuff. an additional email address is just that, an additional email address. I think the terminology might be a hangover from the days of compuserver and AOL. But folk thinking of it as an alias makes them thing it is an alias of something else.

Roseannemst19 is an email address at gmail and in your Thunderbird account settings there should be an entry in the "Outgoing server (smtp) for that email address using the gmail servers and the user name for that email address (usually the email address). If there is not you need to add one.

Matt said

I personally just fail to understand this alias stuff.

If this is sarcasm, it's not helpful. The term used in the Thunderbird Account Settings is "Manage Identities" ... that's what I'm asked about. I posted the question because for well over a year Thunderbird was working just fine until the last update. So, I'm trying to find out what changes, if any, I need to make to my Thunderbird account so that it continues to work to reply with one of the alternate "identities".

Matt said

what server responded?

I answered this already in saying that my email server service provider.

Matt said

Roseannemst19 is an email address at gmail and in your Thunderbird account settings there should be an entry in the "Outgoing server (smtp) for that email address using the gmail servers and the user name for that email address (usually the email address). If there is not you need to add one.

Now ... this might be getting closer to a helpful answer. My "identities" are a mix of gmail, yahoo and rainierconnect. The later is the default, and currently only, smtp outgoing server. I will try adding the smtp for gmail and yahoo, and see if that works.

Matt said

Roseannemst19 is an email address at gmail and in your Thunderbird account settings there should be an entry in the "Outgoing server (smtp) for that email address using the gmail servers and the user name for that email address (usually the email address). If there is not you need to add one.

Adding the gmail outgoing server didn't work. Still get the same error message. See attached image for setup of smtp for gmail.

Can someone, please, offer some helpful assistance? Thanks.

Sorry you think a genuine admission of a complete failure to understand the use of the term Alias or why folk persist in using it as sarcasm. It does however lead to huge misunderstandings as it is a term that has no real definition. ATT sold it to their customers as one thing,. AOL to theirs as something else. Compuserv I think invented it as a meaningless marketing thing. Google also call it Plus addressing. Outlook sell it as something again. Something that only works on their web site, just to add to the confusion.

In order for us to do more than guess please add the troubleshooting information to your post To find the Troubleshooting information:

• Open Help (or click on three-line-icon and select Help)
• Choose Troubleshooting Information
• Use the button Copy to clipboard to select all. Do not check box "Include account names"!
• Paste this in your post.

Personally I think the troubleshooting information will show you sending mail from a load of email addresses using your providers mail server, something that has been frowned upon for decades and actively prevented by many of them in the recent past. for example mail send using a gmail address from say ATT will clearly fail a reverse DNS check and at best be placed in a spam folder, at worst the provider will be blacklisted for facilitating spam.

Have you specified the posted outgoing server entry in the POP/IMAP account for that "identity"