Search Result for "oe": 

The Collaborative International Dictionary of English v.0.48:

OE \[OE]\ ([=e]), A diphthong, employed in the Latin language, and thence in the English language, as the representative of the Greek diphthong oi. In many words in common use, e alone stands instead of [oe]. Classicists prefer to write the diphthong oe separate in Latin words. [1913 Webster]
V.E.R.A. -- Virtual Entity of Relevant Acronyms (February 2016):

OE Outlook Express (MS, Internet)