How can we improve WHMCS?

We used whmcs, for a while and found that if we sent letters according to the smtp mail set up by the system, it would lead to errors in the sending addresses of different work orders.
For example:
System settings: [email protected].
Departmental 1:[email protected].
Departmental 2:[email protected].
If the user submits a work order, it will cause the department 1:[email protected] and the department 2:[email protected] to fail to send the letter, which is prohibited by the smtp provider.

It is recommended that each department set up the smtp function independently.

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