disable OWA URL redirects in emails

 redir.aspx?REF=pq5G9nmgd7aSq8xaGpRVRztdi1S-1xbct4_CrLYu-1bT2zdyiF_TCAFodHRwOi8vd3d3Mi5jY2gub3JnLnR3L2Q4MzAwL3NlYXJjaC8.

 set my URL length to 6144 and query length to 4096 and have not had an issue with this since.

http://www.iis.net/configreference/system.webserver/security/requestfiltering/requestlimits