Hi, I’m having an issue sending to just one domain in particular. I’ve setup an SPF record and I’ve contacted the other IT department asking them to add our domain to the whitelist and they’ve done so but the bounce back continues. I’ve tried searching for answers but have come up with nothing. We’re also not listed on any blacklists. We have Exchange.
There was a SMTP communication problem with the recipient’s email server. Please contact your system administrator.