Option to use external MX and SMTP server-wide

[3246]

As a home server user the drawbacks using email with your set up are PTR records and occasionally going offline (thanks domestic broadband or unreliable 4G).

I use a third party MX provider who queues my mail to mitigate against lost messages during periods of bad connectivity, etc. I also use an external SMTP provider, which can be set on a per domain basis.

Setting an external MX record for a domain means a constant error and the occasional overwriting of DNS records.

Having to set an external SMTP server for each domain can also be a pain, especially when you have heaps.

Please, can we have a configuration option for Cloudron to recognise and avoid overwriting external MX records as well as a way to globally set an external SMTP gateway?