[Dovecot] Time moved backwards

[Neal Becker]

Here's another thought:

>From man ntpd:

 If the -x option
       is included on the command line, the clock will never be stepped and 
only  slew  corrections
       will be used.

       The  issues  should  be  carefully explored before deciding to use
the -x option. The maximum
       slew rate possible is limited to 500 parts-per-million (PPM) as a
consequence of the correct-
       ness  principles  on  which the NTP protocol and algorithm design are
based. As a result, the
       local clock can take a long time to converge to an acceptable offset,
about 2,000 s for  each
       second  the  clock is outside the acceptable range. During this
interval the local clock will
       not be consistent with any other network clock and the system cannot
be used for  distributed
       applications that require correctly synchronized network time.