If you go to the domain.com\Contacts folder in webmail, do contacts exist for the users in question? In MDaemon under Setup / Server Settings / Public & Shared folders, are the options enabled...

The users are using the Look-Out theme.  The problem occurs in all themes. I clicked Hide Unsubscribed Folders to show the subscribe check box, and hovering over the Contacts subscribe check ...

I have been able to find very little information on the CRYPT_E_NO_REVOCATION_CHECK error.   Something in the enviroment is preventing the revocation check from working.  Other than ...

So, it appears from your last message, there's nothing further we can check, or parameters to change to effect  this problem -- which is unfortunate. Thank you for your time on this issue.

MDaemon is using Windows API functions for the certificate checks.  CertGetCertificateChain CertVerifyCertificateChainPolicy MDaemon always logs the errors that are returned, but in this ca...

Are the users subscribed to the domain.com/Contacts folder?  This can be found by going to Options / Folders. Can you confirm that the user has Read access to the domain.com/contacts folder? ...

"can you disable MTA-STS and RequireTLS?" Both had previously been disabled.  I'll certainly pull together today's SMTP (out) log file and email it out ASAP.

If the firewall is showing the traffic coming from the correct IP, I wouldn't worry about the IP that is in MDaemon's log.  We are using the only Windows function we are aware of to get the lo...

"The latest screen shot, which I think is from the firewall, shows the source IP as 192.168.21.251, so does that mean its working? What is reported by the firewall is certainly a step in the right...

It appears your ACL is different from mine with different access rights. Are you signed in as Administrator? Also, your example references an email address as "anyone@". For comparison, I am using...

 As I understand everything is ok there -

What theme are the users using?   Does the issue occur with all themes for the users that are having the issue?

On both of our concerned user's domain contacts folder, the option was unchecked. I did notice however that the option to Add Replies to Contacts was also unchecked, so I checked that, and that so...

You had previously reported that the firewall sees "(127.0.0.1) as 192.168.21.178 " The latest screen shot, which I think is from the firewall, shows the source IP as 192.168.21.251, so ...

Simply stated,  when Mdaemon smtp (out) log shows: Connection established 127.0.0.1:39904 --> 142.251.111.26:25 Our firewall display the bound virtual IP address given to Mdaemon in a clu...

MDaemon is getting the IP that it displays in the logs from windows.  It is using this windows function to retrieve the IP that is being used for the socket. https://learn.microsoft.com/en-us...

The utilities were used previously and did appear to have 'effected' the problem but has not corrected the problem permanently. Certainly, binding to a network card normally works (I’m sure)...

We have been unable to find any issues with the way MDaemon is binding to IP addresses.  If you use the utility to rebuild virtual and physical network cards does it fix the issue again?

Well, correction was short lived.  It seems after a system reboot the system is now back to its same behavior as shown in a previous post in this thread: How can traffic like this be configur...

See if this solves your dilemma: Create a shared calendar on the server using the "Public Folder Manager" rather than from within webmail or the Outlook client. Of course, you would assign access ...