At o2switch, the website and the mailboxes live on the same hosting. That is convenient, and it is the source of the most common misunderstanding: people configure the mail service and forget that the site sends too.
SPF
One TXT record, including o2switch’s sending platform:
v=spf1 include:spf.jabatus.fr ~allThat include authorises every official o2switch sending address at once, present and future. Which is exactly why you should not list IP addresses by hand: they change, the include follows, a frozen list does not.
DKIM
Activation happens in cPanel, under the Email Authentication tool: the key is generated and published in the zone for you, with no DNS work. If your DNS zone is managed elsewhere, cPanel’s zone editor gives you the value to copy to your provider.
DMARC
Publish the monitoring policy on _dmarc.yourdomain.com:
v=DMARC1; p=none; rua=mailto:your-address@yourdomain.comOnly tighten once every sender is identified. The progression, step by step.
Common mistakes with o2switch
- The website sending without anyone thinking about it. Contact form, WordPress notifications, password resets: that mail leaves from the hosting, not from your mailbox. It must be covered by the same record.
- An SMTP plugin pointed at a third-party service (Brevo, Mailjet, Gmail) bypasses the hosting entirely: that service then has to be added to the record, and yours is no longer enough.
- Hard-coded IP addresses instead of the
include. It works on the day and breaks at the host’s first migration. - A second SPF record created for the site alongside the mail one: the two cancel each other out.
Once it is in place, Clarsend reads your reports and shows you what passes, what fails, and who is sending without your knowledge.