Question about Outlook Express

Hi.

Does anyone else have problems with Outlook's e-mail synchronizations
with two different computers (Leonovo Thinkpad with 64-bit W7 EE SP1 and
Office 2010 Pro; 15" MacBook Pro with its Mac OS X v10.10.5 and Office
2011)? Sometimes e-mails don't show up (wrong folders), get left behind
from deletions or moves, show duplicates, etc.? Both Outlooks say they
were up to date and synced.

I do not use these 2 (notebook/laptop)s at the same time since IT
doesn't allow 2 simultaneous VPN connections at the same time. Will
upgrading both Outlooks to the latest versions (Mac's 2016 and Windows'
2013) fix this annoying sync problem? IT uses Exchange 2013 server.

Thank you in advance. :)