This is a bit weird, the same message reported 4 DKIM verifications
with identical details:
2009-10-27 21:30:58 ******-******-** DKIM: d=facebookmail.com s=q1-2009b c=relaxed/relaxed a=rsa-sha1 i=@facebookmail.com t=********** [verification succeeded]
2009-10-27 21:30:58 ******-******-** DKIM: d=facebookmail.com s=q1-2009b c=relaxed/relaxed a=rsa-sha1 i=@facebookmail.com t=********** [verification succeeded]
2009-10-27 21:30:58 ******-******-** DKIM: d=facebookmail.com s=q1-2009b c=relaxed/relaxed a=rsa-sha1 i=@facebookmail.com t=********** [verification succeeded]
2009-10-27 21:30:58 ******-******-** DKIM: d=facebookmail.com s=q1-2009b c=relaxed/relaxed a=rsa-sha1 i=@facebookmail.com t=********** [verification succeeded]
I doubt the message was actually signed multiple times, as other
email from the same domain only outputs one signature verification,
but it's not impossible...