Some emails are not forwarded since I use Cloudflare

I have 2 emails, each one assocaited to a different domain

email1
email2

On the domain host I have a rule set up, so that all emails are fowrarded to a yahoo account.

Unfortunately, some emails get forwarded, some others do not get forwarded.

Those emails not being forwarded are well received into the mailbox from email1, email2, and return an error message to sender as shown in attached file.

Domain host provider told me to set up a txt rule as follows (which I did):

v=spf1 a include: spf.servername.ie ~all

Unfortunately, the issue remains.

Kindly let me know what I need to do in order to ammend the issue.

Sincerely,

Josep Maria NIUBO MARTI