SMTP service fails since 4.1.1

[Matthew Daubenspeck <matt (at) oddprocess.org>]

I am monitoring several servers with SMTP and 2 of the servers suddenly
started having problems since I upgraded to 4.1.1. I haven't changed
anything on the two servers themselves, but they switch from green to
yellow, and back again every few minutes. This is the response when it
is green:

Service smtp on sinclair is OK (up)
554 SMTP synchronization error
Seconds: 0.00

And the page when it goes yellow:

Service smtp on sinclair is not OK : Unexpected service response
554 SMTP synchronization error
Seconds: 0.00

Both servers are running the same version of exim, but haven't been
changed and are running the same version that worked in 4.1.0. Any
ideas? Thanks in advance.

-- 
  Matthew Daubenspeck
  http://www.oddprocess.org

Gentoo Linux 2.6.12-gentoo-r6 x86_64 AMD Athlon(tm) 64 Processor 2800+
19:38:48 up 28 days, 6:05, 1 user, load average: 0.00, 0.01, 0.00