Comment by Gaelan

AWS us-east-1, it looks like:

    $ dig mx purelymail.com 
    ;; ANSWER SECTION:
    purelymail.com.  86400 IN MX 50 mailserver.purelymail.com.
    
    $ dig mailserver.purelymail.com
    ;; ANSWER SECTION:
    mailserver.purelymail.com. 60 IN A 18.204.123.63
    
    $ whois 18.204.123.63  
    OrgName:        Amazon Technologies Inc.

https://awsips.co for the region information