I'm sorry to hear you're having some trouble. I would strongly encourage you to update your mail server. Please keep in mind that version 14.7 is almost 5 years old. More than 3,000 features, changes and bug fixes have been implemented in SmarterMail since then. Because these email clients have received constant updates throughout the years, and your mail server has remained on version 14.7 (which is no longer supported), it's impossible to say whether this is a known issue or something impacting the account/client itself.
I'd also urge you to consider the state of your server security. By running 14.7, you are opening yourself and your users to vulnerabilities, as you do not have the latest fixes, optimizations or technologies at play.
If you upgrade to the latest build and still experience this disconnect between SmarterMail and Outlook, we'd be able to look into this more and escalate a bug report, as needed. If you're interested in discussing an upgrade, I'd be happy to have an associate reach out to provide more information.
I hope this helps!