I have an
IMAP account on a private server and they said me to configure my mail with a
STARTTLS secure connection on the port 993 and authentication with standard password.
How can I set
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First of all, notice that port 993 usually does not use
STARTTLS. If you have been told to use port 993 and
STARTTLS, then that would be very strange indeed. The different between
STARTTLS and ordinary SSL/TLS is the following:
With ordinary SSL/TLS, which is what is usually used on Port 993, the connection immediately starts with an SSL/TLS handshake. In layman's terms, one may say that the connection is immediately encrypted. However, when using
STARTTLS, which is usually used in combination with Port 143, the connection starts unecrypted. The first IMAP commands exchanged between client and server (including the
STARTTLS command) are unencrypted. However, after the
STARTTLS command, both client and server upgrade the unencrypted connection to an encrypted one. That means the SSL/TLS handshake is not done immediately, but only after the client has sent the
STARTTLS command to the server. That's all.
Now sadly, I have experienced that Apple's Mail App does not support
STARTTLS on Port 143 and seems to only support encrypted IMAP connections over Port 993 using SSL/TLS.
I haven't tested this combination, but you should be able to enable it by creating the account as normal (be sure to use IMAP for mailbox access), then going into the Mail application's preferences -> Accounts section -> your account in the list -> Advanced tab, then setting the "Port" entry to 993 and selecting the "Use SSL" checkbox.
A couple of notes may clarify what's going on here:
The second point is the only worry I have here. Port 993 is normally the special port used for the "imaps" service, the go-straight-into-TLS version of imap. But in this case it sounds like the server provides plain-then-STARTTLS service on port 993, which might confuse Mail.app. I suspect it'll work fine, but I don't have a similar server to test with, so I can't be sure.