>My prefix bends bridges and branches in dozens.
>
>My suffix sends mail with what one-hundred governs.
>
>My **i**nf**i**x appears three times, hectic and scattered.
>
>I meet engineers, for the looks always mattered.

This might be pretty easy... but that won't receive the $100$ rep bounty award. <br> You would have to find a secret word in this riddle, involving the numbers, if you want that award. <br> The numbers also include $16$.

<sub>I would give out $50$ instead, but it was my birthday recently, so I am being kind :) ***Note:*** This is genuinely true and not part of the riddle. </sub>

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**Hint:**

>! $100=10\times 10$... but that is not necessarily true for Romans.