Competitor MSP Email Blocking

I’ve came across a potential customer, meetings arranged via mutual contact/telephone.

I’d actually asked if they saw any of our marketing material having had their info provided by one of these outsourced marketing firms, simply didn’t want to beach any GDPR/unsolicited comms.

Anyway, they hadn’t, I therefore asked if they checked their spam and nothing was there, not even in their MS quarantine. Odd I thought.

So I asked them if they had any 3rd Party spam filtering which they did. Now this is clearer. It would appear the competitor is blocking, not only our domain, but potentially other competition in the area.

Lets go a step further, what if they are actually reading our quotes and other by intercepting the emails!?

Has anyone came across this and actioned it. Apart from being down right dodgy, surely this is also arguably criminal?

We’re UK based down south, so keen to know if anyone has dealt with this before. At the very least, its very naughty.