Using thunderbird on dedicated server with Courier IMAP

[gatto]

Hi. I've got a dedicated server with plesk and courier running. I would like to use thunderbird but I'm having a few problems in getting it to run smoothly. First off, I tried the setting "use secure authentication: never" but that didn't work, it took a long time to try and send an email and eventually would come back with a connection failed error. So I'm using "TLS, if available", and that does work. But with that method I have issues with the SSL certificates, and I'm also getting errors here and there on connection timeout failures and other things.. I don't know where to start because there are a lot of issues going on. So I'll just pick one to start, the SSL certificates..

Whenever I send mail it waits a long time, maybe 20 seconds or more, and then shows me the domain mismatch / view certificate dialog box. If I view the cert, it says the cert came from "Plesk, Inc", and if I accept it and close the window, I'll be able to send email again as much as I want as long as thunderbird stays open. But the next time I open thunderbird I'll have to do that same thing again. And every email takes a long time to send, still in the 20 second or more range.

What do you think I can I do about:

A. The SSL cert, so neither me nor my clients with different domain names on my server will have to accept that cert for every thunderbird session.

B. The really long times it takes to get the cert dialog box and to send mail.

Here is what I'm using:

Plesk 8.01
Courier IMAP 3.0.8
CentOS
Thunderbird 1.5.0.12

I'm also running Dr Web Antivirus on all outgoing mails. I don't think that is the bottleneck but I could be wrong.

Thanks!

- Matt

[Kevin]

In order to solve SSL warnings, you need to replace the SSL certificate used by the mail server with a signed certificate issued by a certification authority, and then use the hostname of the certificate to connect to the mail server.

You can only have one SSL certificate per IP address or port number because the certificate is delivered before the client can tell the server what hostname it is using. With Plesk, you should be able to find tips on replacing the mail SSL certificates in the manual. The controls for this would be found in Server > Certificates and Server > Mail, I believe, inside of Plesk.

As far as the slowness, SSL negotiation does have some small additional overhead, but a 20 second delay is not normal and I'm not sure what would cause it offhand.