Hello Weird_Message_Contact,
Thank you for reaching out to Apple Support Communities.
This may be appearing from a junk email received by your device.
These steps may help:
Mail
From the Mail app, open the email that has the contact that you want to block, then tap the contact at the top. Tap Block this Contact.
Additional details can be found here: Block phone numbers, contacts, and emails on your iPhone or iPad
If the issue persists you can try to prevent this from happening by disabling Siri & Search for Contacts:
Change Siri settings on iPhone - Apple Support
Change which apps appear in search
You can change which apps appear when you search with Siri.
1. Go to Settings
> Siri & Search, then scroll down and select an app.
2. Turn settings on or off.
Cheers!