Arrive with post, ultimately attracted by TV serial (9,6)
I believe the answer is:
situation comedy
'tv serial' is the definition.
(type of TV programme)
'arrive with post' is the wordplay.
'arrive' becomes 'comedy' (I can't justify this - if you can you should give a lot more credence to this answer).
'with' means one lot of letters go next to another.
'post' becomes 'situation' (both can mean a job).
'comedy' put after 'situation' is 'SITUATION COMEDY'.
'ultimately attracted by' is the link.
I am not very happy about this link. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for situation comedy that I've seen before include "Funny series on radio" , "Bottom perhaps" , "Spoof" , "TV series noted for its humour" , "TV programme" .)