This is a full walk through of the “Courier of Favor” quest, including the two sub-quests, “The Nonad Brothers” for Pagus Nonad and the taxes quest for his brother, plus “The Postmaster’s Challenge”, for Postmaster Aric Songfairer.
Find Pagus Nonad in Sunrise Hills (that’s the housing zone, off the NW corner of the Guild Lobby - click the gates and select any of the neighborhoods). Pagus is on find (ctrl-f), and he is in the first building you come to, by the kiln or forge. Ask him about his brother (no, there’s no hint in game that you should do this). Then go to Postmaster Aric Songfairer, behind the building. Ask him about the League of Antonican Bards, and accept the challenge (note: you must do this, or the bard quests you do next won’t count).
There are four destinations for the bard quests - Qeynos, High Keep, Freeport and Kelethin: so collect all the post for one destination at a time. However, there are sixteen places with mail, including all four of the destinations, which means that there is a strategy to follow. Whatever you do, you will have to visit at least one destination twice; once to collect, once to deliver.
An evil race/class character may be able to do this quest, provided they can invis past guards, and have decent Bard faction (kill lots in Mistmoore to fix).
Say “deliver to xxx” to collect.
Deliver to Jakum Webdancer and Idia (pouch from Freeport) in the Bard Guild.
Deliver to Felisity Starbright and Ton Twostring (one pouch) in the Bard Guild in East Freeport.
Deliver to Tralyn Marsinger and Eve Marsinger (one pouch) in South Qeynos at the Bard Guild.
Final delivery to Lislia Goldtune.
Then there is the Nonad quest; this can be completed entirely within the Qeynos area (South and North plus optionally Qeynos Hills); it has a sub-quest of the Taxes collection. You will need an empty inventory slot to collect and combine all the collections.
Vicus Nonad is upstairs in the white building east of the Lion’s Mane tavern. Give him the cough tonic, then tell him you will help with collections; don’t forget to ask for the list, as you have to hand it back to him before you are done. Say “tax collection” to each of them; they should all be on find, apart from Flynn, who is in Crow’s Tavern. You can skip Mira Sayer if you wish, and go direct to Flynn and say “Mira Sayer taxes” - and then do what he says.
In North Qeynos:
Make sure you hail Pagus Nonad when you get back to Sunrise Hills before speaking to Lysric (this is needed to complete Lysric’s quest).
Back in Sunrise Hills, find Lysric Loresinger in Sunrise Hills. Lysric is on find (ctrl-f), and she is behind the first building. If you haven’t already, hail both Aric and Pagus to complete their quests. Hail her and receive the bag.
Total time was around 2 hours, including a few mistakes; 1 hour 25 minutes on a second attempt with a porter.