Have you tried sending to yourself? A possibility that exists with all web-hosted email accounts is that the appropriate security settings, such as DKIM and SPF, may not be properly configured, causing the email to be rejected. If messages to yourself are not being received, I encourage you to contact Bluehost tech support to investigate.

I have only been sending to myself using a different email address as the recipient. The bluehost online webmail works perfectly, so I assumed it was not their settings that needed adjusting. From my perspective, only Thunderbird is having an issue, so I assumed it must be a setting in Thunderbird that needs attention.

Was that a wrong assumption?

Thank you for the suggestion though. I will follow up with Bluehost in the meantime to see if they have any insight as well.

Webmail does not use the same setup configuration. If you send from yourself to yourself and the mail doesn't appear, bluehost is rejecting it. If there was a configuration problem, bluehost would not have accepted the message for sending.

Update: Bluehost is having me add a new DNS record to improve my email's reputation. They believe that is why the emails are not making it back to Thunderbird. I have to wait for that to propagate, but I will report back later if it works or not.

Update: after adding two new DNS records, Thunderbird will now send and receive emails to and from myself. However, I still can't get through to my gmail account. Does Gmail require additional DNS security measures? I am so over my head here. Any help is greatly appreciated. John

You have confirmed that your email account now works. But Gmail is very picky. If gmail is ignoring you, there is a problem somewhere in your account settings, not settings that you do, but settings that the server administrator (bluehost) does. And, server admin stuff is over my head. Maybe, someone here with that knowledge will add more info. I believe it relates to DKIM and SPF settings but, again, I am not familar with that.

Update: After adding a new DNS record, the Webmail works now completely, but I still can't send an email to my gmail account from Thunderbird.

Recap: I have a new Bluehost email account. Using the Bluehost(Titan) webmail app, I can send email to myself and to my gmail account in Thunderbird. From Thunderbird, I can send email to myself using the new email account, but I can't send email from using my new email account from Thunderbird to my gmail account.

I've checked Gmail's webmail browser to make sure and they are not arriving there either.

So I'm stuck. It works from the Webmail app on Bluehost, but not from Thunderbird. Why might that be?

Thanks

It's like I said; the problem is how your account is configured on the server, not by you but by bluehost. Webmail is its own world and has nothing to do with mail sent from your PC. Receiving email servers generally compare the domain name (it is not bluehost.com) with the server itself (which IS bluehost.com) and then checks to see if that is a scam. Finding no integrity check that the bluehost server is legit for your domain, it rejects the message. Ok, my explanation isn't technical, but that's what is happening. This problem is not uncommon when setting up email accounts on web hosting sites Thunderbird is not the problem.

Thank you for the explanation. At this point, I'm hoping someone with an insight into what Gmail is looking for will chime in. Bluehost doesn't seem to know for sure, but they are more than willing to give me records to try out. Seeing as how the functionality has increased incrementally since I started tinkering with them, this does seem like the right track. Just not there yet.