Here in Israel, we regularly ferry back and forth via travelers to and from America and other lands, such things as birthday gifts to grandchildren, hand-crafted holy items (my profession is writing holy scrolls on parchment), payment for same, etc. Someone’s going to New York, “please take along with you this gift for my nephew” or a megillah (scroll of Esther). Those coming back to Israel bring back payment for the latter, which they deliver to my eldest son in Jerusalem who gets it back to me. I call it the “shlep-along express”.
Something similar can be done within the US with truck drivers and other professional travelers. Sealed envelope, remuneration for the courier upon delivery of the envelope still sealed. Totally under the radar.
Another idea was suggested to me that all members of the correspondence committee share usernames and passwords of a few e-mail addresses. User 1 drafts a message and saves it as a draft. User 2 opens the email, reads and deletes the saved draft, and drafts a response in the same way. Users notify their correspondents of a message via innocuous and unrelated e-mails.
There’s also an encryption method that I know.
“User 1 drafts a message and saves it as a draft. User 2 opens the email, reads and deletes the saved draft, and drafts a response in the same way.”
IIRC, I think that’s how Petraeus and his mistress communicated. (Maybe not Petraeus, but one of those guys.)