title: Will PickupDeliveryLocation work when using an outgoing mail server on a different domain than our own?
body: <p>What happens when the outgoing mail server is not part of the local domain?  For example, I work for company xyz.com and our smtp server is mail.xyz.com.  We host client sites in a multitennant application.  We allow our users to point to their own smtp server using email configurations we store in our database.  </p>
  
  <p>The code we use to send emails loads the configuration with the smtp information and the authorization needed to send an email on behalf of our clients through their email system.  </p>
  
  <p>Currently we are running into concurrency issue that is causing timeouts for various clients when notifications are being processed.  They are currently configured to be sent immediately.  I've read that moving to the local pickup directory can solve this issue.  </p>
  
  <p>I am concerned if I specify a path like C:\Temp\Mail but use an SMTP connection to a clients mail server is that going to work?  Doesn't the email being created and sent from the pickup location need to be on the same domain as the smtp server?  </p>
  
  <p>How will the clients SMTP server know .eml file has been generated for their domain and needs to be sent out without having to change our client's environment?   If someone can provide any information as to how the SMTP and Specified Pickup Locations work I would greatly appreciate it.</p>