Great question — answering as the UphillTech team:
I was able to do it as follows: Type mail , it tells me how many unread messages I have. Let's say, 31. Type t 1-31 , it displays all messages from 1 to 31 in a big concatenated sheet ( turned out that t * achieves the same result, thanks to Jaime Hablutzel ) Type q to quit view mode, type q again to quit mail That's it! mail says all 31 messages saved in your mbox file, and next time you enter it, it will say "no mail for you".
Full answer by Vlad Nikiforov: https://askubuntu.stackexchange.com/a/1234967 (CC BY-SA 3.0).
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