version 1.12.0-664 pro, Android 4.0.3
Exchange server account (OWA).
after app update, Contacts lookup returns records beginning with "EUM:email@domain.org;", among with other record containing e-mail.
replying to a user with address on Exchange, it makes look-up automatically, and sens e-mail address to the first record found, which is "EUM:....". obviously, such a message will be rejected by recipient.
previous versions worked fine (since i skipped several updates, i'm not sure when the bug appeared first) - "EUM:.." records were excluded from contacts lookup results.