[MlMt] Port error where port defined?

[mail at assai.com.au]

I'm in Lesotho, where bandwidth is narrow.

I'm getting this error:

"Cannot make a secure SSL connection as requested. The server does not 
support it on port “143”. You may want to provide an explicit port 
in the IMAP settings or disable the SSL requirement"

However, on that account, I DO have ports explicitly defined: 993 for 
IMAP and 456. The server is gmail.com.

David