Hi, Robin,

Please provide more details. My understanding is that IMAP works, so are you downloading messages so you can switch to another email provider? Please explain and we can go from there. Nice to see you again. :) david

David 'n ALL,

Oct. 7 I started getting the following response when trying to send e-mail using TB 115.10.1 (32 bit, Sony Vaio SVE 17122CXB (64 bit) Sending of the message failed. An error occurred while sending mail. The mail server responded: [F1-Auth] Authentication Required, must login.. Please verify that your email address is correct in your account settings and try again. Our ISP could NOT help. Wanted me to use Zimbra (which seems to be ?junk?! I still cannot send messages. Iam logged in/on sincee I have no trouble getting messages. The ISP won't help with TB.

If TB won't work - function after all these years, I need to know NOW! I have to get SEND to work or scrap TB.

Following up on David's previous reply: "Please provide more details. My understanding is that IMAP works, so are you downloading messages so you can switch to another email provider? Please explain and we can go from there."

David, yes, apparently IMAP 'works' for getting mail with TB.

I am paying our ISP & have been for e-mail for over 20 years. Thus, I shouldn't have to (nor do I want to learn a new ISP's system)!

I am stymied why I recently have SO MANY problems! I dare not move years of incomplete - ?corrupted? messages to the new Win 11 laptop (used, not 'new').

All remain WELL & be SAFE!

Robin

Robin,

I presume you are using Zimbra's settings - https://wiki.xmission.com/Zimbra_Email_Client_Configurations as I don't think you have posted screenshots of settings. It may be that, if you post a screenshot of your SMTP server settings pane, some suggestions will be forthcoming. That;s the best I can offer.

ALL,

As before, I am confused, just MORE CONFUSED!

I received (apparently) a link re: how to use / set up Zimbra.

Apparently as before I cannot type - write clearly. I wrote our ISP only provides tech support for Zimbra. I do not know - understand Zimbra. I do NOT want to have to learn Zimbra. For years I've had few, if any, problem with Thunderbird!

I WANT to use TB, but as I stated every time I now try to send e-mail, now for 4 or 5 days I'm hit with, " Sending of the message failed. An error occurred while sending mail. The mail server responded: [F1-Auth] Authentication Required, must login.. Please verify that your email address is correct in your account settings and try again."

I NEED help to find AND correct the problem! If someone can help, please respond ASAP. I now have several messages I cannot send.

Thanks! Remain WELL & be SAFE!

Robin

Dave,

My memory is going FASTER than I thought. I can do - use Print Screen, but if I 'knew' how to add - include it in on this response.

I tried saving the 3 print screens as - in HTML, but this communication will not allow me to attach it. Server Settings Server Type IMAP Mail Server

                             Server Name   mail.duo-county.com Port 993
                             User Name      dulca@duo-county.com

Security Settings Connection security SSL/TLS

Outgoing Server (SMTP) mail@duo-county.com - mail.duo-county.com (Default) dulca - smtp.duo-county.com Authentication method Normal password

I'm HOPING the above is some help since I can't print screen.

Remain WELL & be SAFE!

Robin

Unfoirtunately you ISP has made changes and while they appear to be determined to be friendly, they have failed entirely in their quest to actually provide information on their change.

I can find a couple of posts in Facebook here https://www.facebook.com/duobroadband

Those basically indicate the Duo have decided to use Zimbra as a web portal for their web mail. There is also information indicating that there was some sort of migration of mail to this new portal. What is missing is any information that actually explains what that all means and particularly what if anything it means for those using a mail client with the settings the still publish in their website. https://duobroadband.com/e-mail-setup/

I also checked the DNS records for the site in the hopes that would shed light. All it did was suggest that the email server may actually be hosted by Microsoft. The registered mail exchanger being duobroadband-com.mail.protection.outlook.com

Details here https://intodns.com/duobroadband.com

So I doubt at this point we can help you much without some information from your ISP. 1. Are the settings on this page still valid? https://duobroadband.com/e-mail-setup/ 2. What are the updated settings that should be used for POP IMAP and SMTP? (it have serious doubts the answer to 1 is yes. So this is critical to successfully connecting to get your mail. Connections settings are something the server owner/server administrator specifies, not the mail client application.

In addition to that;

1. Do you have an antivirus? Which is it?
2. Do you use a VPN? Which is it? (note many antivirus products now included a VPN and some like the one that comes with Norton is difficult to turn off and get to stay off.)

If you could post back with those four things, then we will be on the way to progress. It is just a shame your ISP makes such poor user support documentation.

Matt (& Dave, sorry if I forgot someone!),

Your wrote/asked: I can find a couple of posts in Facebook here https://www.facebook.com/duobroadband

Not sure if you saw/read my response prior to your detailed post? Since I couldn't figure out how to make Print Screen 'files' all I could do was type out the settings. As far as I know you are correct, duo's suggestions are not my settings. They indicate POP3 but their support people had me use IMAP.

You wrote: I can find a couple of posts in Facebook here https://www.facebook.com/duobroadband

I am not using Facebook. grrr

In case I was not clear, I have NO trouble getting mail. I CANNOT send mail!

You wrote:

   Do you have an antivirus? Which is it?
   Do you use a VPN? Which is it? (note many antivirus products now included a VPN and some like the one that comes with Norton is difficult to turn off and get to stay off.) 

NO anti virus. NO VPN

If you could post back with those four things, then we will be on the way to progress. It is just a shame your ISP makes such poor user support documentation.

Hopefully my reply contains requested answers. Sadly any problem(s) I had during the previous 20+ years the ISP's tech support could be resolved. After Oct. 7, 2025 when the ISP changed to Zimbra, and the tech support company could NOT help me get the POP3 and Thunderbird working then had me change from POP3 to IMAP. grrrr

Someone please help me accomplish making print screen(s) a file so I can attach it-them. Swimming against the current is exhausting me, taking time (& brain power I lack), and using TB support (hours between my reply & the TB community's response).

Remain WELL & be SAFE!

Robin

I offer two possible free screenshot tools:

- MWSNAP is available at https://mwsnap.en.softonic.com/

- Windows has a built-in screenshot tool. A how-to link is here: https://mwsnap.en.softonic.com/

Dave,

Got the link, downloaded, & installed it. Now, I need to find understandable instructions.

Please write what screen shots are needed, I'll try to promptly provide them!

Remain WELL & be SAFE!

Robin

Robin, I don't think you need it on this issue, since you already posted the contents. Still, it's worth the time to get familiar with the tool. - First, start the progran - then, click to the screen you want to capture - now, click back to MWSNAP - now click the 'capture' button in MWSNAP and then select 'any area' and then click mouse for upper left corner and drag to lower right corner. and then save.