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% replaces any number of letters (la% - lake, lamp)_ replaces one letter (ca_ - car, cat)

Crossword clues for E-mail subject line abbr.:

FWD: E-mail subject line abbr.
ATTN: E-mail subject-line abbr.
FWD: Repeated abbr. in the subject line of a chain e-mail
EOM: Abbr. signaling that the subject line contains the full content of an e-mail