With the original to be submitted later

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Note added at 7 hrs (2018-09-12 22:02:59 GMT)
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It simply means after you send the form by fax, you will still need to provide its original copy afterwords.

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Note added at 1 day 10 hrs (2018-09-14 00:44:18 GMT)
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Your 站经理is supposed to send《油气站员工转正报批表》by fax to our 管理部

if you look at this structure before the term in question, you'd understand the of any phrase that contains "to follow" to translate 正本候补 won't work.

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Note added at 1 day 10 hrs (2018-09-14 00:48:16 GMT)
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"original to follow" works only if the sentenece is rewritten this way:

We are sending 《油气站员工转正报批表》by fax to the 管理部(original to follow).

However, the whole sentence is totally different in meaning to the Asker's original sentence.