Problème d'envoi emails : "I'm sorry to have to inform you that your message could not

Bonjour à toutes et à tous,

Mon nom de domaine est : blasepheme.com
Et j'utilise l'offre : support standard

Je rencontre la problématique suivante :
Il m'arrive très régulièrement de recevoir des emails d'erreurs après mes envoies d'emails :
Avec comme objet : "Undelivered Mail Returned to Sender"
Mais ça ne concerne pas 100% de mes emails. J'ai fait des tests.
J'envoies mes emails à partir de Gmail.

Voici le genre de message que je reçois :
> This is the mail system at host mo582.mail-out.ovh.net.

> I'm sorry to have to inform you that your message could not
> be delivered to one or more recipients. It's attached below.

> For further assistance, please send mail to postmaster.

> If you do so, please include this problem report. You can
> delete your own text from the attached returned message.

> The mail system

> : host asav2.iinet.net.au[27.32.32.49] said: 550
> #5.7.1 SPF unauthorized mail is prohibited, please verify your domains SPF
> records at https://dmarcian.com/spf-survey/ (in reply to DATA command)

ou

This is the mail system at host mo583.mail-out.ovh.net.

I'm sorry to have to inform you that your message could not
be delivered to one or more recipients. It's attached below.

For further assistance, please send mail to postmaster.

If you do so, please include this problem report. You can
delete your own text from the attached returned message.

The mail system

: host smtp-in.sfr.fr[93.17.128.123] said: 550 5.7.24 SPF
permanent error: (in reply to end of DATA command)


phidias.gmXsfr.fr: said: 550 5.7.24 SPF
permanent error: (in reply to end of DATA command)


Vous avez en effet introduit une erreur de syntaxe dans votre SPF:

"v=spf1 include:mx.ovh.com **include** include:1mail.commail.com ~all"

Que fait ce mot "include" là, tout seul ?