[exim] So Exim will break lines on Subject?

So I’m sending an email with a subject that looks like this

addlist Fidelity Fixed Income New Issues:intray.zalerts.fidelity.research:0

but I’m noticing that when the final text file is stored in Maildir that the subject looks like this

Subject: addlist Fidelity Fixed Income New
Issues:intray.zalerts.fidelity.research:0

ie. the newline has been added.

Is that normal behavior?

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