Where does “postmark” come from?

I can't write this etymology because the chain provided contains circular repetitions (English post → Latin post → Latin postis → English poster → English post...) that don't form a coherent derivational path. A valid etymology requires a linear progression from older to newer languages without loops. Could you provide a corrected chain, or clarify the intended derivation for "postmark"?

postmark (English): A marking made by a postal service on a letter,...

Definitions

  1. A marking made by a postal service on a letter,...

Ancestry of “postmark”, step by step

postmark traces back through two separate lines of ancestry.

via English post

StepLanguageWordMeaning
1EnglishpostA long dowel or plank protruding from the ground;...
2Middle Frenchposte
3Italianpostamail, post; post office; stakes
4Latinprobāre
5Latinprobōto approve, permit, commend
6LatinProbusgood, serviceable, excellent, superior, able
7Proto-Indo-Europeanpro-bhwo-being in front, prominent
8Proto-Indo-Europeanpro-toward, forward
9Proto-Indo-Europeanpor-to give birth; forward, through; going, passage
10Proto-Indo-Europeanper-before, in front; first; to go through
11Proto-Indo-Europeanpr̥tóspassed , crossed

via English Mark

StepLanguageWordMeaning
1EnglishMarkAbbreviation of Markarian
2Germanmarkmark any of various European monetary units
3LatinMārcus
4LatinMartīnus
5Latin-īnusof or pertaining to; -ine
6Proto-Italic-īnosof/belonging to
7Proto-Indo-European-iHnosCreates adjectives of materials
8Proto-Indo-European-no-adjectival suffix
Every word from Proto-Indo-European pr̥tós