Why configure SPF for Gandimail? The answer is pretty simple. With an SPF record in place for the same, you are technically specifying to your email receiving MTAs that Gandimail is one of your authorized senders. This can hugely benefit your deliverability rates.
Creating an SPF record for Gandimail
GandiMail recommends you add the following TXT records in your DNS depending on the services you use:
@ 10800 IN TXT "v=spf1 include:_mailcust.gandi.net ?all"
For Simple Hosting:
@ 10800 IN TXT "v=spf1 include:_spf.gpaas.net ?all"
For GandiMail + Simple Hosting:
@ 10800 IN TXT "v=spf1 include:_mailcust.gandi.net include:_spf.gpaas.net ?all"
In all of the above, “@” is to be entered in your Host/Name field, 10800 is your TTL, and TXT is your resource Type. DO NOT publish more than one SPF record for a single domain. If you have an existing record, simply modify it to include Gandimail.
Note: Publish the simple hosting TXT record mentioned above only if you send emails through your website (e.g. via contact forms).