Based on our record, InstAddr should be more popular than Followup.cc. It has been mentiond 3 times since March 2021. We are tracking product recommendations and mentions on various public social media platforms and blogs. They can help you identify which product is more popular and what people think of it.
I'll update this if I find more. For now, this seems to be a partial solution. It's a Gmail add on (except I don't use Gmail) that adds reminders. The options when setting reminders include cancelling it if someone replies, and to remind everyone in the thread. If you combine those two, it seems like — if you use Gmail's web client and have $23/month you're dying to get rid of — a decent way to add the feature. Source: over 1 year ago
I'd recommend https://m.kuku.lu/ for e-mails. You can choose your own username, password and also use 2FA and don't need to enter any additional information. I also use it for school mail. Source: about 1 year ago
You can get a .jp address at https://m.kuku.lu/. Source: over 2 years ago
InstAddr for temp email without losing the email account. You choose when to delete it. Source: almost 3 years ago
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