The mail trains certainly pass through Stafford and I’ve seen them in that platform over the last few years pre-Covid but whether it was there to load/unload or just waiting time/broken down I’ve no idea.
Class 325s use the mail platform on test runs from Crewe electric depot after maintenance. An out and back "runs as required" working has regular timetabled paths as 5G20 11:35 Crewe IEMD - Stafford and 5K21 12:51 return, although this working is cancelled far more often than it runs.
Another "as required" working off Crewe electric depot, around the same time of day, is 5A91 11:21 Crewe IEMD to Willesden PRDC, which is a much more frequent runner (the corresponding working in the other direction is a 5K07 00:22 Willesden PRDC - Crewe IEMD). These workings are the ones currently used to get 325 units to and from Crewe for planned maintenance.
I keep seeing these mail trains on real time trains but had no luck in trying to actually see one go through Crewe yet!
Anglo-Scottish mail services are booked through Crewe southbound at 10:07 (1M31 MSX) and 20:10 (1A97 SX) and in the northbound direction at 18:20 (1S80 MSX) and 18:48 (1S96 SX)
If the platform isn't used with mail trains, when did mail train use end?
The mail services were gradually thinned out during 2003, with the last TPOs and other mail trains finishing at the beginning of 2004. For some general background on the mail trains before and during the "Railnet" era, the YouTube video "Railnet - Royal Mail's £150m Waste" by Ruairidh MacVeigh is worth watching (some good BR-era archive footage used!)
GBRF restarted some London - Shieldmuir services with 325s in Dec 2004, although initially these were loco hauled, as in this shot of 87022 at Rugeley -
https://www.flickr.com/photos/wulfruna_kid/28670626015
This means that, as far as I know, there has never been a December without at least some mail trains running to help with the extra volumes of Christmas mail!
I was looking at some old copies of Freightmaster to see which trains might have called at the platform at Stafford. Searching these headcodes in flickr found some nice photos which illustrate some of the trains calling there, at least the loco-hauled ones:
12:44 Plymouth - Shieldmuir mail on 08/09/99 with a class 86 -
https://www.flickr.com/photos/britishrail1980sand1990s/17151558763/
1F43 20:12 Birmingham New Street - Warrington RMT (portion detached off 1E43 15:09 Plymouth - Low Fell) - here with a GNER liveried Class 90 in 2001 -
https://www.flickr.com/photos/shawfordjunction/40337709781
1S96 16:00 Willesden - Shieldmuir, with 90034 in 2002 -
https://www.flickr.com/photos/63513902@N05/49709155342/
1V68 1946 Shieldmuir to Cardiff TPO with 90016 in 2002 -
https://www.flickr.com/photos/jason15c/50975555342/
1A93 21:18 Carlisle to Willesden TPO with 90017 -
https://www.flickr.com/photos/andy_masons_gallery/15815705892/
For comparison, this is a nostalgic photo of the pre-Railnet era at Stafford, with a class 81 on a TPO set in 1987 -
https://www.flickr.com/photos/tutenkhamunsleeping/5373686998/
There are Royal Mail terminals at Shieldmuir (Motherwell), Warrington Dallam, Doncaster, I think Tyne Yard, and the Willesden Hub all purpose built, like Stafford, for the introduction of Class 325 and providing level loading/unloading for roll cages, there may be others from this era I am not aware of.
I seem to remember hearing that the increased height of the Railnet platforms would have caused problems with opening the doors on traditional passenger stock! The Railnet trains did call at various places with standard height platforms - this picture shows some sort of portable ramp being used to transfer the "York" trolleys from platform to train at Carlisle -
https://www.flickr.com/photos/75784477@N08/41276163512
Considering that the use of 67s on mail trains didn't really start until 2000, the same year the final Railnet terminal opened at Bristol Parkway, the heyday of the "Railnet" system was a very brief period from 2000-2002.
A nice misty shot of 90033 on a TPO at Stafford (probably 1V68) as the era faded away -
https://www.flickr.com/photos/nat37670/22069651818/