# How to Change the Number of Mail Server Connections

If multiple mailboxes are used by using multiple parallel mail clients running an IP address, some clients may not be able to connect to the server.

#### FOR THUNDERBIRD:

In this case, under **Tools** / **Account Settings**, select the **Server Settings** under the mailbox.  
Click the **Advanced** button, then in the **Maximum number of server connections to cache**, reduce the set value to 1, and then click OK.