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I currently use a hosting package that is used both for the website and emails. Since it is a shared hosting the IP is sometimes blacklisted so our emails are considered SPAM and are bounced back. I want to setup Google Apps account, only for the email addresses, to avoid the situation of emails considered SPAM because of blacklisted IP. I plan to setup the DNS (provided by the domain registrar) with a domain mx records that points to google mail servers, and keep the A records (for the website) to point to the shared hosting server.

I wonder how will the destination email server react in a case when we send email via google mail servers, but still use our own domain name? Will the destination mail server still check whether our shared hosting IP (resolved with our domain name) is blacklisted, or it will only consider the google mail server IP?

Thanks!

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You're on exactly the right track.

Mail is sent using the domain's MX record, if it's present. If it's not, it'll use the A record for the domain. So if you setup an MX record pointing to Google's mail servers, that's the IP address that will be checked against Blacklists.

This came up on ServerFault: https://serverfault.com/questions/381460/emails-are-regularly-blacklisted-due-to-being-hosted-on-a-shared-blacklisted-s

Analogy You put a sign on your mailbox at home that says "No Flyers". You know that the Mail-man will respect it. Yet you come home every evening and your mailbox is still full of fliers. To combat this further, you hire a security guard to watch your mailbox. But you only want him watching the mailbox, and not inspecting the actual contents of your mail. So you go around your neighbourhood and find out who, other than the mail-man, delivers flyers and you put them all on a "blacklist". You give this blacklist to your security guard and instruct him to not allow any of those people to put anything into your mailbox. Now whenever someone approaches your mailbox, the security guard ask the person who they are, and checks if they're on the Blacklist. If they are, they get maced. If they're not, they can put whatever they want to in your mailbox. The security guard doesn't care who the mail is originally from, or what's in it. He only cares about who's delivering it so that he can stop people that he knows deliver flyers.

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  • Thanks. Let me precise the question again, I want to be sure that your answer reflects what I really want to ask. Regarding the sending of mail, online gmail interface will be used. The destination mail server will receive email from google mail server. However our own domain name will also be present in the mail header. I wonder if the destination mail server will also run blacklist checks for the A record of our domain name or only for the google mail server? May 2, 2013 at 15:41
  • The receiving server is only concerned with the IP address of the server that's actually sending the mail, not the IP address of the domain that it claims to be sending on behalf of. Of course there are other spam filtering methods that will be based on the full e-mail address, content, etc. But the "blacklists" only list servers, so if you were to run your domain name through a blacklist check, it will see your MX record as a Gmail server, and test that against the blacklist. Your domains A record would only be checked if you didn't have an MX record. May 2, 2013 at 18:18
  • I've added an analogy to my answer, I hope that somewhat clarifies things. May 2, 2013 at 18:39
  • Brilliant analogy, very much appreciated! May 2, 2013 at 19:10

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