[LUAU] iPhone can only get IMAP email from wifi, not LTE

[Brian Chee]

The situation is where iPhones can get to IMAP email only if they're not on
the AT&T cellular network. Wifi is fine, but not 3G nor LTE.

So while this IMAP server is on Solaris, this is also possible on Linux
versions.

So since this gave us soooo much grief, I thought I would share, in hopes
no one else has to suffer.

Brian Chee


Hi All,

Xxxxxx got his new iphone and I set it up.  He thought by getting the new
phone the mail checking problem would go away.  I verified that it didn't
go away.  I did get much further in figuring out what the problem was
though with the help of Brian Chee.  It turns out it has to do with att
proxying the phone connection and dns not reolving it correctly.  So the
imap daemon was saying there was a hostname mismatch.  After a lot of
searching, it turns out the problem is tcp_wrappers.  specifically that the
tcp_wrappers in solaris 10 is compiled with the -DPARANOID option.  Even
though we had it set to allow ALL for imap/imaps, it was still doing the
dns check.  Even removing the hosts.allow and hosts.deny files didn't
help.  What helped was disabling tcp_wrappers all together with the
following 2 commands.

  inetadm -M tcp_wrappers=false ; svcadm refresh inetd

After I did that, the phone worked great.  I obviously didn't want to leave
tcp_wrappers off completely and found out how to turn off a specific
service.  so I enabled tcp_wrappers again, and then I turned off
tcp_wrappers specifically for imaps.  After I did that, things started to
work again for the iphone on att's network.  These are the commands I used
to reenable tcp_wrappers and then turn it off for imaps.

  inetadm -M tcp_wrappers=true
  inetadm -m imaps/tcp tcp_wrappers=FALSE
  svcadm refresh inetd


Ross



Sent from my iPad