this may not work, and usual "touch the registry at your own risk" warnings apply...
you could try setting the following registry keys to a larger number.
HKEY_CURRENT_USER\software\Microsoft\Internet Account Manager\Accounts
The settings will be within the separate account folders. For example:
Manager\Accounts\00000006 The keys for the server timeout settings are:
"IMAP Timeout"=dword:0000012c "SMTP Timeout"=dword:0000012c
values are in hex in seconds...