kroyster wrote:
Just to clarify, sending/receiving email over SSL (which is supported) will secure it in
transit ...
No, it will not. Using SSL to connect to your SMTP server to transmit e-mail will provide the following security: (a) your username and password for your SMTP server, sent from your iPhone to your SMTP server, will be encrypted; and (b) your e-mail will be encrypted between your iPhone and your SMTP server. However, once the e-mail you are sending is past your SMTP server and on the way to its intended recipient, it is in the clear.
A similar story applies for using SSL to connect to your IMAP (or POP) server to retrieve your e-mail. SSL will protect: (a) your username and password for your IMAP server; and (b) the e-mail you are receiving, from your IMAP server to your iPhone.
End-to-end encrypted e-mail is something entirely different. That is, if you want e-mail encrypted all the way from your iPhone to the recipient's computer/iPhone/etc.; or, if you want e-mail encrypted all the way from the sender's computer/iPhone/etc. to your iPhone, you need a different solution. PGP or S/MIME encryption of e-mail would be necessary.