Allowing a domain to send emails via another domain

Question

I have two servers:

• www.website1.com
• www.website2.com

I have another server www.website3.com which I want to be allowed to send emails in behalf of the first two websites. How do I do this?

Solution

Assuming that both website1.com and website2.com have SPF records, add a:www.website3.com to each of those SPF records.

Edit: you write "So if I have 10 servers, it means editing the DNS zones for those 10?".

Yes, it does. Each domain's SPF record is authoritative for itself. However, if you have many domains that should all have identical records, you can change the first one, say website1.com, to include all the relevant information, then the others can reference it by defining each of their records to say just v=spf1 redirect=website1.com.

You'll still have to edit all 10 now, but you can avoid having to do it again later.

Comments

[Steve-o]

include

[Dave]

So if I have 10 servers, it means editing the DNS zones for those 10?

[Dave]

Thanks for the quick reply. That's really tedious. I wonder if there is another way besides using SPF records.

[MadHatter]

Hang on, are you saying you don't have SPF records right now? If you don't, then there's nothing stopping you sending email right now from www.website3.com claiming to be from website1.com.

[Dave]

My problem are spambots. SPF records help ensure my mails don't get marked as spam.

[MadHatter]

OK, that's great, and I'm glad you're using SPF - but since you are, it's SPF that prevents you from sending email from www.website3.com claiming to be from website1.com. The only way to change the function of your SPF records is to, well, change your SPF records! If you want a faster way of editing your ten DNS zone files than "by hand", well, that's different - ask a new question with some examples of your zone files, I'm sure someone will post a sed or perl script quicker than boiled asparagus.