Thanks for the report, Ton! I was able to replicate this issue in the latest release, 16.3.6775, and I've forwarded the details to the development team.
As an aside, please keep in mind that this forum is mainly intended for user-to-user interaction. While our team does participate, we unfortunately can't get to every single post. For a direct reply, I'd recommend submitting a ticket to the Sales or Support Department using the Tickets button above. We're typically able to reply to requests within 4 business hours. You can start with the Sales team first. If it's not something we're able to reproduce, we would recommend a ticket with Support, keeping in mind that tickets and/or ticket costs are refunded if the issue is determined to be caused by a bug.
Thank you again for helping to improve SmarterMail! We'll add an update here when the issue has been resolved.
Andrea Free
SmarterTools Inc.
877-357-6278
www.smartertools.com