How do I clear out all these unknown TikTok addresses from Mail on my iMac?

tried to access my addresses to send an email and got a whole list of tiktok addresses while I have never had tiktok and my normal addresses were all mixed up with addresses that I never had, yet my iPhone addresses were all as they always were. How do I get my addresses back as they were and get rid of tiktok.

Thanks

Raya

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