how do I get STARTTLS working with sendmail on FreeBSD 10.3 ?

[Ian Smith]

In freebsd-questions Digest, Vol 668, Issue 5, Message: 12
On Wed, 22 Mar 2017 22:41:54 -0400 William Dudley <wfdudley at gmail.com> wrote:

OK, I'll join in this messy top-posting orgy, rearranged somewhat and 
including some bits pasted in from earlier posts.  I've been reading 
these - not carefully enough - without being able to put my finger on 
what weird thing is going on here until Jim pointed out the obvious:

 > >> On Wed, Mar 22, 2017 at 8:18 PM, Jim Ohlstein <jim at ohlste.in
 > >> <mailto:jim at ohlste.in>> wrote:
 > >>
 > >>     Hello,
 > >>
 > >>     On 3/18/17 6:44 PM, William Dudley wrote:
 > >>
 > >>         A google search does not reveal a useful answer.
 > >>
 > >>         I just want to use a self-signed certificate so I can get my
 > >>         email from my
 > >>         FreeBSD mail server to my cell phone.  My FreeBSD server runs
 > >>         sendmail.
 > >>         I don't really want to switch to postfix, qmail, etc. etc.
 > >>
 > >>
 > >>     I'm sorry to be the one to break it to you after all this time and
 > >>     effort, but AFAIK Sendmail speaks neither POP3 nor IMAP so you
 > >>     cannot use it as an MDA. You can use it to *send* email from your
 > >>     phone, but not to retrieve it. You also can use it to forward mails
 > >>     to another email address from which you can retrieve it, of that's
 > >>     what you want.
 > >>
 > >>     If you want to retrieve emails using your phone's email client, you
 > >>     will need an MDA. I use mail/dovecot2.

And earlier, William, you'd stated:

 : I just want to use a self-signed certificate so I can get my email 
 : from my FreeBSD mail server to my cell phone.  My FreeBSD server runs 
 : sendmail.

and more specifically:

 : The point of this exercise is to allow my Android phone to access my 
 : email on my FreeBSD 10.3 server, using imap.  I had it working last 
 : year, and then, with nary an error message, it stopped working.  So 
 : the email client is the native Android email client (on a recent 
 : Cyanogen Android).  My FreeBSD server runs sendmail, and I've been 
 : running my own mail domain for about a decade.

"Using imap", right?  Not SMTP, which your Android client will use to 
SEND mail to your/any SMTP server, but IMAP (or POP3 if you prefer), 
which means picking up from an IMAP (and/or POP3) server, right?

Jim is absolutely right here: sendmail does not talk IMAP, nor POP3.  

It receives messages from other SMTP servers, or clients, and sends to 
other SMTP servers.  That's it, ignoring the intermediate submission 
agent dance.  It transmits from its mailqueue, and receives into user's 
INBOX, from where IMAP/POP3 accesses it.

 > There's another layer in there, popd or imapd or whatever, but the point
 > is, I've been
 > using sendmail on FreeBSD for at least a decade.  I had STARTTLS working
 > with sendmail
 > just last year.  So your assertion that I have to run some other MTA could
 > not be true.

I've been using sendmail since '98, but still don't use STARTTLS, which 
is why I've steered clear of this topic to date :)

Well, is it imapd/popd/popper or whatever?  Whatever, that's what your 
phone will be talking to.  Does IT require STARTTLS to deliver mail to 
your phone?  Does your phone require STARTTLS to pickup from a POP/IMAP 
server - mine sure doesn't.  Has anything changed in $whatever's setup, 
or requirements?  I think that's where you should be looking.

 > But thanks for your time.  I welcome all suggestions, even ones that don't
 > pan out.

I suggest acknowledging Jim is correct, and figure out what's wrong with 
your $whatever.  Other contributors including Matthew - whose knowledge 
is far beyond mine or most people on this subject - perhaps, like me, 
hadn't twigged that your problem is pick up, NOT sending from sendmail.

cheers, Ian