Execution of authentication request returned unexpected result 404

I use 2 diferent PC for check my email. On one PC i have old ver : 6.0.19861.0 and the another i have the last ver: 7.2.34062.0.
On the 1 pc i get this error:
-Synchronizing folder: "My email"/Directory/ failed with an error: Execution of authentication request returned unexpected result: 404() 

-Synchronizing folder: "My email" /Contacts/ failed with an error: Execution of authentication request returned unexpected result: 404() 

On the seccond pc i get this error:

-[XMAPP] An attemp to conect to “My Email” failerd. This could be caused by temporary server unavailability or incorect settings. Do you want to check the settings?

Everytings works fine till 5 or 6 january…then i get this errors .

I have seen this a lot.  I think the issue is with your anti-virus software.  Try disabling the AV software and see if the sync works.  If so, you will have to include an exception in your AV software for mailclient.exe.

It appears that an AV software update is messing up existing exceptions.

Is not from my AV software. Already try before post here.