That's good news that you've found the problem. However the fact that the value is now encrypted should not be an issue as the API methods were updated to encrypt/decrypt the values as necessary

There are a few 7.2.0 installs that had issues during upgrading, where the full upgrade set of steps did not apply. As the code that initially encrypts the smtp password is the final step, it can mean that the smtppassword fails to encrypt - and thus when the API accesses it (e.g. on the host settings page) it tries to decrypt an unencrypted value and fails.

We added code in 7.2.1 to capture this case and resolve any issues (i.e. detect that the value was unencrypted and encrypt it).

 In DNN 7.2.0 the API was updated to use the secure methods for storing and retrieval of the smtp values so as long as the API was being used the values would be perfectly usable - obviously if some code read the value directly from the database (i.e. skipping the API method) then there could be an issue, but we do not support direct database access so module developers are recommended to use the API methods i.e. use Host.SMTPPassword . I'm guessing that your module either used direct table access or else use the lower level API method (HostController.Instance.GetString("SMTPPassword")) which is not aware of the encryption. Either way a change to Host.SMTPPassword will fix it.

thanks.