Siemens S7 318-2 memory question

i'm using the 318 anda cp343 to send emails. i've got an outgoing mail queue made from data blocks programmed into my project in case there are network outages the emails can pile up until the net comes back up (they're used for inventory control and are processed offsite).
currently i only have about 100k of RAM left over after the program loads for use in my mail queue.
it's all working great, but i need more storage.
there's a flash/ram card slot on the front of the processor, but i've only used them to store a copy of the program for an initial load.
is there a way to utilize that flash/ram card as data block storage and turn it into my mail queue? or is it strictly for initial loading of the program?

I've not used a 318, so I can't give you a definitive answer, however, it may help to bounce the question back up.

With the newer MMC-based 300-Series CPUs, you could do what you want, using the MMC card. Since the 318 is actually a 400-Series CPU in disguise, maybe somebody who works with the 400s on a regular basis could help - S7Guy, perhaps?

the word from siemens:

the 318 is an odd bird. takes special flash/ram cards.

for me, i went with RAM...
part # 6es7-951-1al00-0aa0 for a 2 meg card.

the program can't directly access the ram card like onboard RAM, but it can use it for data block storage.

when you define the data block, you have to set it as "unlinked" so it'll store on the card instead of loading into ram.

but to actually make use of those blocks, you have to move them back into system ram via an SFC20 block move.

so i can store the outgoing messages as data blocks on the ram card, and if/when i have to resend, i can recreate the message by moving the appropriate blocks back to ram and rebuilding the message.

This is the same situation as the MMC cards for the newer 300-Series CPUs, they also can only be used for data block storage. Mostly used for storing recipes, from what I've heard.