I have created a new domain. When I send an e-mail, it always arrives at the recipient as spam. However, this only happens if I send the e-mail via my laptop, because if I send it via my smartphone, it does not arrive as spam.
Can you do anything against that?
Is the email sent with the smartphone via WLAN or just the mobile data? About mobile data on the smartphone you have a different IP address and a different configuration of the operating system or the mail program used. Basically, I would once check the laptop for malicious programs / viruses and restart the router for an IP address change.
For many hosters, where the domain is registered, you can set a TXT entry for the so-called SPF record of the domain, which increases the trust factor for the recipient server.
https://www.spf-record.de/generator
That should help, ask questions
You should send a short e-mail via the PC and once via the smartphone to you or a friend.
Then you could post both emails in the raw version (!) With all headers etc. Here, so you can compare them. Possibly. Then you find the decisive difference.
The e-mail programs have to do something different.
