Thunderbird Community Forum

Good day,

I have a site that I use for my Tia Chi Walking classes and lately I'm not receiving any communications from them. I've reported the issue to their support team and they responded with this error they've received when they try to send an email to me from the site: https://esmerise.com

smtp; 421 4.4.1 Unable to connect to remote host | 421 | TransientCommunicationFailure

The email address that I use is from my ISP Spectrum.net, however I use Thunderbird to sync all my emails. I contacted Spectrum support and they are not seeing this error, all emails appear to be coming through with them.

Please advise if anyone has experienced this issue and if so, how was it resolved.

Thank you Billie

I have a POP3 account which will not download new emails. The indication is there are no new emails. I can access the email account through gmail and there are many new emails. I have checked password. I have gone through the re-indexing procedure and all other possible solutions I could find. I did find some information about Java and incidentally, there was a Java update on the day my emails began to fail, 8-16-2026. I found this error message, but I don't know how or if I can fix this: module is not a constructor ExtensionCommon.sys.mjs:1679:15

   asyncGetAPI resource://gre/modules/ExtensionCommon.sys.mjs:1679
   AsyncFunctionNext self-hosted:780

Thank you for any help you might provide. Please email to [redacted email from community support forum]

Having issues sending e-mails due to message: "e-mail not sent. Cannot connect to SMTP server 47.43.26.4 (47.43.26.4:587) connect error 10060" Requires 2-6 attempts to send. Also, problems with sending attached files, claiming to be too large.

One day after windows update, my thunderbird can't not download email from yahoo, microsoft, google..etc I tested the connection be fine but I can't recive any email

Hi, Last week, Thunderbird stopped receiving & sending emails with CenturyLink. I can access CenturyLink emails via their website and on my android.

Using Google, it said the configuration should be changed to CenturyLink's settings. It looks like Centurylink changed the settings for legacy email "centurytel.net". I went to CenturyLink website and copied their settings the best I could.

https://www.centurylink.com/home/help/internet/email/how-to-set-up-your-email-server-settings-to-go-through-pop-and-smtp.html

1. CenturyLink website shows changes to the following settings.

       a.	Incoming Server:  POP:  pop.centurylink.net    Port: 995, Security:  SSL
       b.	Outgoing Server:  SMTP:  smtp.centurylink.net    Port:   587     TLS if available
       c.	Username:  Full email address which for me ends with @centurytel.net

2. Thunderbird settings are: (screen print attached)

        Incoming:  POP: pop.centurytel.net  Port:  995, & Security:  SSL/TLS.  
        Outgoing SMTP:   Server:  smtpauth.centurytel.net    Port:  587,  & Security:  STARTTLS

I only changed the POP and SMTP server names. The security settings could not match up exactly since the drop down options did not have SSL and TLS individually. I left the original settings Thunderbird had of SSL/TLS for incoming and STARTTLS for outgoing. A screen print of Thunderbird's original settings is attached.

After following the settings configuration setup in Thunderbird, entering my correct password, I received this Authentication error: "Unable to log in at server. Probably wrong configuration, username or password." That's as far as I can go. Thank you for any help you can provide.

Hi I have just set up AOL accounts for 3 email addresses on Thunderbird. I have set them up as pop accounts and each account can receive emails and send emails ok but the really strange thing is they won't send from one AOL email address to another AOL email address which is something we quite often do as as family. All have pop.aol.com and port 995 along with smtp.aol.com and port 465. Hopefully someone will know what is going on.