Yes, SiteGround supports SSL over IMAP/POP3/SMTP.

Information on how to configure different mail clients to work with IMAPs/POP3s/SMTPs can be found in the following articles:

• Outlook Express

http://kb.siteground.com/article/How_to_configure_Outlook_Express_with_IMAPs.html
http://kb.siteground.com/article/How_to_configure_Outlook_Express_with_POP3s.html
http://kb.siteground.com/article/How_to_configure_Outlook_Express_with_SMTPs.html

• Mac Mail

http://kb.siteground.com/article/How_to_configure_Mac_Mail_with_IMAPs.html
http://kb.siteground.com/article/How_to_configure_Mac_Mail_with_POP3s.html
http://kb.siteground.com/article/How_to_configure_Mac_Mail_with_SMTPs.html

• Outlook 2003

http://kb.siteground.com/article/How_to_configure_Outlook_2003_with_IMAPs.html
http://kb.siteground.com/article/How_to_configure_Outlook_2003_with_POP3s.html
http://kb.siteground.com/article/How_to_configure_Outlook_2003_with_SMTPs.html

• Thunderbird

http://kb.siteground.com/article/How_to_configure_Thunderbird_with_POP3s.html
http://kb.siteground.com/article/How_to_configure_Thunderbird_with_IMAPs.html
http://kb.siteground.com/article/How_to_configure_Thunderbird_with_SMTPs.html