Thunderbird Outgoing Email Problems – SMTP Configuration Scenarios
The first part of this article begins with the post Outgoing Email Problems with Thunderbird. You might want to check that out for some background information.
I will start with some of the common SMTP configurations that I see. If you use a major ISP and your configuration is different, please post the name of your ISP and the configuration details in the comment section. Also, if you know of a publicly accessible page where the ISP offers configuration information, please post that as well.
Lets get started.
First, the Thunderbird configuration section for SMTP server settings can be found at:
- Select Account Settings from the Tools menu.
- Scroll down to the bottom of the list if e-mail accounts.
- Select Outgoing Server (SMTP).

The section that you want is at the top of the right-hand side.

Highlight an SMTP account and click the Edit button, or if you want to add a new account click the Add button. The SMTP Server dialog box will pop up.
The Description is not important, but if you configure multiple SMTP accounts it would be a good idea to enter a description. The Server Name and the User Name are the two important areas to focus on. You will need to get this information from your hosting company or ISP. The account name is usually just the primary account name from your ISP. That is the name to the left of the @ in your primary e-mail address. With some ISPs it is important to use the primary account name and not necessarily the account name for the individual e-mail address you are using.
You do not need to set up separate SMTP accounts for each e-mail address if you have multiple e-mail accounts set up with the ISP. In fact, most ISPs allow you to run all of your outgoing e-mail through their SMTP servers, so if you find that one SMTP server works well, try selecting it for each of your e-mail accounts.
Typical AT&T SMTP Configuration in Thunderbird

- Enter the SMTP Server Name. There are many variations of this, depending upon which AT&T e-mail service you are using. You will need to get the correct server name from your AT&T service provider.
- Make sure that “Use name and password” is checked.
- Use the full e-mail address for the primary account.
- AT&T e-mail uses a secure connection. Click on the SSL radio button. The Port will change to 465 when you click the radio button.
AT&T Support Info: How to verify At&T email Settings.
Typical Cox.net SMTP Configuration in Thunderbird

- Enter the SMTP Server Name. Cox uses different SMTP servers for different geographic regions in the USA. Get the proper SMTP server name by contacting Cox.
- Make sure that “Use name and password” is checked.
- Use the account name for the primary account. Thunderbird will prompt you for the password the first time you send e-mail.
- Cox does not use a secure connection. Leave the No radio button selected.
Typical GMail SMTP Configuration in Thunderbird

- Enter the GMail SMTP Server Name.
- Make sure that “Use name and password” is checked.
- Enter your account name. If the e-mail address is myaccountname@gmail.com, the account name is myaccountname. Thunderbird will prompt you for the password the first time you send e-mail.
- GMail uses an encrypted connection. Make sure that the SSL radio button is selected.
A Very Important Final Step

Do not forget that if you set up an additional SMTP server configuration, you must select it in the Account Settings for each e-mail account you want to run through that server. Right click on an account name and select properties to view the Account Settings. You may also have to clear the password assigned to an account when you switsh SMTP servers. Follow the instructions in changing Thunderbird passwords to do so.
Some Additional Notes
- Always get the proper outgoing email configuration information from your hosting company or ISP.
- Don’t rule out the possibility that your PC might be causing the problem. Try temporarily disabling your virus software and firewall to see if either of these systems is blocking outgoing e-mail.
- If possible, set up multiple SMTP configurations so that if one fails, you can switch to another. I run most of my mail through my Cox SMTP server because I have found it to be more reliable than AT&T. However, both accounts have gone down periodically. Mail servers run into problems just like any other server. Sometimes the customer service people that you call are completely unaware of any issues with server downtime.
- If you are using a Yahoo account for e-mail, be aware that Yahoo changed their system configuration a while ago. See the following page for more information: Yahoo Outgoing E-mail Problems with Thunderbird.

Dr. Anton Fnatt Says:
I DON’T UNDERSTAND ANYTHING.
I have been ‘on air’ for over 10 years and have taken care of my favourite email accounts from the beginning of dawn.
Every now and then I reformat my PC and reinstall my favourite email program – Mozilla Thunderbird – with say – 14 email accounts. An absolute multiple account setup? Not many months ago I started to get trouble, emails from all accounts went out fine however the FROM address seemed arbitrary. I don’t understand why while sending from the SAME account but to different receivers, my FROM address changes between the email address that I sends from while other emails (to other friends) are sent with the email address to the default SMTP address that is common for all my 14 email addresses. This is really annoying because I cannot respond an email and believe it is returned to the same address as it was sent to. This process is completely consistant, one specific incoming email will always use the same outgoing address – but I have no control of what email address. It shall not be like this.
TE Says:
Hi Doc
I don’t usually post rants, and this does fall into that category. I get plenty of rants from people frustrated with software problems. Trying to solve many of these problems is similar to the blind men describing an elephant, because the software doesn’t give you a clue as to the root of the problem. That means that we have to resort to a method that I call, ‘poke and hope troubleshooting’.
If I understand your problem correctly, Thunderbird is randomly changing your reply-to address on your outgoing e-mails. Make sure that you specify a reply-to address for each account in the Account Settings. For some reason, Thunderbird does not fill this in when you set up a new e-mail account.
I don’t know why you might see an arbitrary e-mail address in the reply-to, but specifying an address may fix the problem.
Let us know if this works.
george Says:
thanks
this worked for me
Frank Says:
The Edit/Accounts setup page allows entering multiple SMTP’s.
My problem is that I have no idea how to control which one is used! Making the second one in the list the default one is of no use, since T’bird continues to use the first one in the list. Only by deleting all but one can I force use of that one.
TE Says:
Hi Frank
Setting the order of the SMTP servers with Thunderbird doesn’t do anything. You should be able to select the SMTP server assigned to each e-mail account on the Account Settings page for each e-mail address. The selection is Outgoing Server. Make sure that you click OK to save your selection.
Brian Says:
I was having the same issue with not being able to send e-mail. I have 2 accounts, both of which get used regularly for different things. What solved it for me (using AT&T Yahoo) was to set up the outgoing (SMTP) server settings for each account separately, even though they are using the same server. Once I did that, it worked fine. Hopefully, it will continue to do so! Happy holidays!
Ken Says:
TE, I use Thunderbird for my business account, now it has worked fine until I switched to AT&T. I have talked to my webhosting agent and he said that everything is configured correctly with them but when I told them I was using AT&T, they said that they were probably the problem. Now I recieve emails no problem, but I can not send them. I have contacted AT&T and they told me that they don’t know what I am talking about. Below are me configurations. Please help!
Description: NSG Account
Server Name: mail.navystudyguide.net
Port: 25 (I have tried port 465 as well)
Security and Authentication
User Name: billing+navystudyguide.net
No SSL and I have tried with SSL which switches to port 25
TE Says:
Hi Ken
You are not using AT&T for your outgoing e-mail. This configuration has nothing to do with AT&T. If you want to use AT&T accounts, you have to run them through the AT&T mail server. Try using the AT&T configuration shown above.
For e-mail accounts related to your web site, you have to determine which configuration works best with your mail server. That information should be supplied by your hosting company. You may have confused the hosting tech when you mentioned AT&T and he assumed that you were running outgoing e-mail for your web site through AT&T. The AT&T tech was probably also confused because the configuration has nothing to to with AT&T.
If you are trying to run your web site e-mail through the AT&T SMTP server, you have to set it up using an AT&T account. In other words, set up the SMTP configuration for AT&T and then select that SMTP server in Thunderbird. Do not use the username and password for your web site account because the AT&T server will not recognize it.
Generally speaking, you can run your e-mail through any outgoing SMTP server where you have an account, but some ISPs do not let you run e-mail from other ISPs and e-mail accounts through their servers.
Sunvolt Says:
My Tbird receives, but will not send email. I recently uploaded Tbird because my bootleg version of Outlook 2003 would no longer update. My web host and email server is Godaddy. I set up the account with online support from Godaddy. All outgoing email sent at first, but then I found I had to resend in order for it to transfer. Then, something shut off my Virus Protection. I was using AVG. It was no longer operating. I tried AVG uninstall to no avail. I was able to upload Avast!, so now I had Virus Protection but still could not uninstall AVG, and in addition, I could no longer send email. I have rechecked my “Account Settings” for Tbird and they seem to be set correctly. Is there a glitch with AVG/Avast!? What do you think?
Sunvolt
Doogie Says:
Hi Sunvolt
It is difficult to determine the nature of the problem given the limited information Thunderbird provides when there is a problem. Other software can create problems that are not obvious.
If you suspect AVG is the problem and need to fully uninstall it, try some of the tips I found on the following web page:
http://www.pchell.com/virus/uninstallavg.shtml
Antivirus software can sometimes be very difficult to remove. If you think Avast is causing the problem, try temporarioly disabling it and then test Thunberbird outgoing e-mail.
Cindy Says:
I’m new to At&t dsl service and am on a mac using Thunderbird. I. like many others can not send e-mails. It keeps ask for my password but keeps rejecting it. I’ve tried everything I have seen suggested. I haven’t seen any comments about AT&T-Thunderbird-Mac. I’ve been working on this problem all day.
Hope you can help! Thanks!
Doogie Says:
Hi Cindy
That does not necessarily mean that the password is wrong. It is getting rejected by the mail server because some part of the connection is not correct. For most AT&T email services you must check SSL because AT&T requires a secure connection. Also, make sure that the server name is correct. If you cannot connect, call AT&T for support.
Joey Says:
I use Thunderbird at work, at a college, and they recently switched our email over to a new server (IMAP). I can pull my mail off of the server with no problem, but I can’t send email. I thought I had the settings correct, per what IT told me the changes were, but I still get this: “An error occured sending mail. The mail server sent an incorrect greeting. *OK CommuniGate Pro IMAP Server 5.2.14 at ****.edu ready.”
The server for both in and out going mail is mail.****.edu, port 143, with no ssl.
Am I doing something wrong? How do I fix this?
Doogie Says:
Hi Joey
Something has changed with the SMTP server settings. SMTP is for outgoing (sending) messages. POP and IMAP are for incoming (receiving) messages. It looks like you are trying to send messages through an IMAP server. It would be unusual for both the incoming and outgoing mail servers to be named the same. Check with your IT person again. The SMTP settings are wrong.
Asbjorn Nesse Says:
Hi,
I work very often with my laptop in different but well known networks. Meaning I have all actual SMTP adresses. But, the way it is done know my going through the meny and set as default is not a very easy way. I’m looking for a button in the menu with text telling me which SMTP is set and a click on that button I can make the change.
Is that easy to do and how??
Best regards
Asbjorn Nesse
Norway
Doogie Says:
Hi Asbjorn
You can select an SMTP server from the list of SMTP servers you have set up in Thunderbird, but you have to do it on the Account Settings page. Just right-click on any account in the left-hand window in Thunderbird. That brings up the Account Settings display for that account. There is a drop-down list on the right side named “Outgoing Server (SMTP)” where you can then change the SMTP server assigned to that account.
If you have not already done so, you can set up as many SMTP servers as you wish on any Account Settings page. The Outgoing Server setup is the last selection on the list of accounts.
Frank Says:
I’m having trouble with the compose feature of Thunderbird. I have five email accounts all with individual outgoing server settings and one-to-one identities. Recently, I have discovered that every time I go to compose a new email, another duplicate set of identities is listed in the “From” pull-dwon menu. There are now so many duplicate identities (and even cross-identities that I never established) that I can’t reach one of the From domains that I’m using quick frequently now.
Has anyone ever run into something like this? Any ideas (short of a full reinstall?)
Thanks, Frank
Tom Says:
I have an SMTP issue that is driving me batty. I have just downloaded Thunderbird to a work computer on which I’ve been using Outlook. I have entered, re-entered the SMTP name and user name and even copied and pasted from my Outlook settings, but no luck. The server always rejects the send request. Any thoughts?
Doogie Says:
Hi Tom
It can be frustrating to resolve these issues. There are so many interactions involved with an e-mail connection that it is hard to identify the root of a problem. Plus, it doesn’t help when software only offers generic error messages that do not tell you anything that you do not already know.
Experiment with the settings, such as SSL. Restart Thunderbird after each configuration change.
Make sure that you have the correct Outgoing Server selected on the Account Settings screen.
Try calling tech support at your ISP.
It is also possible that a firewall or security software on your PC is causing the problem by blocking the Thunderbird connection. We have seen intermittent problems with Norton Anti-Virus blocking Thunderbird connections. This appears to happen just after Norton does an automatic virus definitions update. Re-booting the PC re-starts Norton and usually resolves the issue.
Ritergal Says:
This information needs to be updated for version 2.0.0.23 (20090812). The structure of the Outgoing Server configuration changed a couple of versions ago. I have an incorrect setting and although I’ve been using Thunderbird for years and am probably considered an Advanced User, I cannot figure out how to edit this error.
Doogie Says:
Hi Ritergal
What changed? What error? What incorrect setting?
I’ve been using Thunderbird for several years and I have not seen a change in the SMTP server settings. Perhaps something changed on your PC or with your hosting company. Some hosting companies are blocking the use of their SMTP servers unless the e-mail is coming from one of their e-mail accounts. Some anti-virus programs can also create problems.