Techs / Devs, just a quick question:-

Apart from the additional resilience provided by having mail queued in Xeams whilst Exchange might be down, what other benefits are actually present when running Xeams in SMTP server mode over Proxy mode..?  I am having troubles really identifying any weaknesses Proxy mode has over SMTP mode in order to make the move to setting up SMTP server mode as the preferred option?
The only benefits I presently see are:
1. Extra resilience as mail can be stored until exchange is back up (proxy mode cannot do this)
2. Exchange is not exposed to MAIL commands
3. Spam is dealt with at the front door before even contacting exchange server
4. The hiding of the SMTP banner and the mail server used internally (Proxy shows this)

P.s. I am not talking about outbound mail via smart host as that will add many features such as DKIM, DMARC. 

I am just talking about incoming email via Xeams in SMTP server mode.

Many Thanks!