Hello darsheville / Kaeascannethakt,
Please provide the below details:
1) Your OS Version and Architecture ?
2) Scalix Version and release ?
3) Client version where message sent
4) Client version where message was received
5) Outlook is using via scalix outlook connector or IMAP/POP3 for the sender and recipient ?
and could you please create support ticket.
Scalix Support Team.