Can't send mail with attachments

I’ve tried both SMTP and Exchange and get the same workflow termination message each time:
Exception: Could not load file or assembly ‘Microsoft.Exchange.WebServices, Version=, Culture=neutral, PublicKeyToken=31bf3856ad364e35’ or one of its dependencies. The system cannot find the file specified.

I’ve installed the Exchange Web Services Managed API 2.0 and then 2.2 when that didn’t work, but nothing changed. Any suggestions? I can send emails from standard SharePoint Designer workflows without issues.


Please write me at [email protected] we can setup screen sharing session to resolve the issue.

It turned out that it is necessary to recycle IIS application pool.