This is a set of fake SMTP servers that'll accept any email and just show it here. No emails are actually sent for real.
fake-smtp.littletools.app
unavailable
Sample curl command:
echo "From: from@ex.co To: to@ex.co Subject: Hey Date: $(date +'%a, %d %b %Y %H:%m:%S') Test email content" | curl smtp://fake-smtp.littletools.app:undefined --mail-from from@ex.co --mail-rcpt to@ex.co --upload-file -