On Monday, June 28th, 2021 at 1:13 PM, Migadu Support support@migadu.com wrote:

On 28.06.21 04:53, nadashin wrote:

...

When I tried to send a mail from a envs.net mail account to one of your

user sir@cmpwn.com the mail failed to deliver.

delivery status contained -

Remote-MTA: dns; aspmx1.migadu.com

agnostic-Code: smtp; 554 5.7.1 <mail.envs.net[5.199.136.28]>: Client

host

rejected: Access denied

Hi

Thank you for reporting this!

Well we should definitively not prevent you to get in touch with Drew,

so we're taking immediate action :)

The subnet 5.199 has been used in major attack on us recently and it got

blocked by us in the firewall. We've however now placed other

protections in place and knowing there are valid senders we will avoid

blocking the higher subnet next time.

You can now try resending again.

Thanks again & happy mailing!

Dejan

/Migadu