[horde] Active Sync problem with plain text messages

[Mohamed Aly]

I am working on horde 5.1.1 and having a problem with active Sync when
someone send plain text  email "not HTML" the message will be delivered
normally to my inbox but not synced with my mobile using active sync . but
everything is working fine with HTML emails. any help?

horde 5.1.1
active sync: with support to "Exchange 2007 SP1 EAS 12.1"


Thank You