SPAM sent to 'sub'-accounts (email1(_at_)domain)

I´m receiving tons of spam sent to non-existing e-mail accounts, such as 
hermann1, hermann2, hermann3 (and so on). My clients are also being 
targeted by the same SPAM.
Is this recipe below safe enough to run and catch these SPAMs???

:0
* ^TO:.*(1|2|3|4|5|6|7|8|9)
/dev/null



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