That's easy: my "side hustle" is selling NOS DeLorean parts: transaxles, gull wing doors, flux capacitors, etc. Whenever a client arrives from that era they самиздат the emails to me; I send them via mcvax to SDSC, so in a day or two they're gatewayed via scdc.edu to unimelb.edu.au, and Bob's your uncle...
(Alternatively: if one can root the NVRAM on the Cosmic Management Engine it's possible to have mail stored by Vishnu before each cataclysm restored by the next Brahmā, thence passing to our time by normal flow. Recall that control theory tells us any sufficiently lagged input phase ultimately behaves like a lead)
