Is there any benefit in using VPN to send out cold emails / transaction emails / authenticatoon emails as ISPs tend to mark the id of the entire organization as spam basis the IP address even when marketing or authentication / transaction emails have a secondary domain id. What is the best practice here to avoid the ISP marking the other email ids from primary domain which does not do any such bulk activity as spam and especially different offices across many cities despite the activity being done from a centralised office only

Use multiple subdomains+ e-mails

Okay. Does your ISP also play a role in blocking your domain or marking it as spam even if you use multiple su domains and emails right way

Drop me a dm I can help you

Sure