Knowledge Base

Get Expert Website Hosting

Choose website reliability and expertise with SiteGround!

Home / Email Support / Email Configuration / You may have exceeded the maximum number of connections to this server.

You may have exceeded the maximum number of connections to this server.

Last update: Jul 03, 2025 1 min read

The default number of maximum allowed IMAP connections in Mozilla Thunderbird is set to 5. Depending on the specific IMAP configuration on the server hosting your account, this may result in the following error message:

Unable to connect to your IMAP server. You may have exceeded the maximum number of 
connections to this server. If so, use the Advanced IMAP Server Settings dialog to 
reduce the number of cached connections.


Get Ready-To-Use Email Prompts

Get Ready-To-Use Email Prompts

Download our free ChatGPT email prompt templates prepared by AI professionals. Try them out to create engaging and successful emails in no time.

Google reCAPTCHA used. Privacy Policy and Terms of Service apply

 

The solution is to reduce the maximum number of connections in Thunderbird. This can be done from Edit > Account Settings > Server Settings (under the mail account for which the setting should be modified) > Advanced > Maximum Number of server connections to cache.

Change the maximum number from 5 to 1 and the issue should be resolved.

Want to learn more about email and SMTP troubleshooting? Download our comprehensive ebook – it is all that you need to solve similar errors with ease!

Share this article