So setting up my shiny new iPhone 3G for IMAPS email was not entirely straight forward.  (-:  There are two complicating factors that I ran into.  For IMAP over SSL (IMAPS) connections to a mail server that is using a digital certificate that is signed by a well known certificate authority AND running on the default TCP port 993, no problems.  You may have a be a bit patient as the mail app on the iPhone accepts the certificate.  For less standard mail server implementations, read on …

I am using a server certificate that is in essence a self-signed certificate – it is signed by CAcert.org, however very few (if any) browsers and mobile devices trust or even know of CAcert.org.  In this case, you will need to be patient while the iPhone mail app finally rejects the server certificate as untrusted.  The dialogue box will acknowledge the mail server certificate is invalid and will ask if you want to continue.  Accept the continue option and eventually (took about 5 minutes for my iPhone) the iPhone will accept the ‘invalid’ certificate.

Now, if you are using a mail server that has IMAPS running on a non-standard port (anything other than TCP 993), you must first establish the connection and have the iPhone accept the certificate over port 993.  Once the mail account is setup initially, then you can go change the port to something non-standard.

Once I get a chance I’ll post some screen shots.