Do you have the signature in use on your phone? Mostly I find folks with images in their signature, either only images or lots of them have reception issues because of spam filters. Sometime all that is required it to put some text after the last image.

Emails sent from my desktop (with thunderbird email program) are the problem. I was only mentioning that I can send emails (from same email address) from my phone (which does not us Thunderbird email program) without any problems just to demonstrate that Thunderbird is the likely culprit (vs. maybe my email server, etc.). Again, only on my desktop (with thunderbird program) emails are showing as sent, but no one is receiving them. Not just certain people, but everyone I send to is not getting them (even parties to which I regularly email daily) This just randomly started yesterday

I asked if you used the same signature on your phone. I have 9 lines of response totally unrelated to the question. Please answer it.

No. I do not use any signature on phone emails, but DO use a signature on emails sent from desktop via Thunderbird.

rbhansen said

No. I do not use any signature on phone emails, but DO use a signature on emails sent from desktop via Thunderbird.

And that is probably the cause of your difficulties. Try sending mail from Thunderbird without it.

Appears that removing signature fixed issue of receipt on other end. How very random for this to just suddenly be a problem. Any suggestions for a way to add signature again w/o causing problems, or just cant use signature anymore?

as I said tsome folk hav had success simply by add-inf text int the signature. One spam tool refused mail that ended in an image, so just adding text aftr the images works.

The whole realm of anti spam is murky to say the least. Everyone is second guessing the senders of spam, why? Because government, particularly in the USA is not prepared to address the issue. Why things happen with certain spam filters is a very difficult question that really can only be answered by those that are dropping the mail..

A few weeks back my outgoing emails were showing as sent, but no one was actually receiving them, and I received no bounce-back notices. Messages sent from mobile phone were getting to receivers, but not emails sent from desktop. The problem was corrected by omitting any signature from the outgoing emails on the desktop. I AM NOW HAVING THE NEARLY THE SAME PROBLEM YET AGAIN (emails show as sent but no one is receiving them) and it is now happening with emails sent via mobile phone and desktop. The prior cause of problem (signature on outgoing emails) is still turned off/removed.