PowerMTA same virtualMTA for multiple relay users


Sometimes you want to give the same pool of IPs to different apps/users of your smtp relay service. You may want to give one set of credentials to marketing department, another set of credentials to billing department. Both department will share the same IP pool aka virtualMTA pool. Here is an example configuration:

# start userlist (authenticated with SMTP AUTH protocol) 
<smtp-user username1>
    password changemetosomethingreallysecure1
    source {authorized_users}
<smtp-user username2>
    password changemetosomethingreallysecure2
    source {authorized_users}
#end userlist

<source {authorized_users}>
    always-allow-relaying yes   
    process-x-virtual-mta yes    # allow selection of a VirtualMTA based on 'x-virtual-mta' header
    max-message-size 0           # no size (in byte) restriction on submitted messages
    smtp-service yes             # present SMTP service to these users
    require-auth true
    default-virtual-mta mta-pool1