In Cuba, web access is extremely censored, so I created a tool that allows more than 50,000 people to browse the Internet through email. Cubans send me an email with an URL in the subject line, and I email them back with the response. Read more at https://apretaste.com.
It was working like a charm, till the communist government of Cuba started blocking my emails. My solution was rotation.
I started with Amazon SES, and I was changing the domain each time it was blocked, but Amazon adds a header to all emails, and once they blocked the header no email from SES was able to reach Cuba any more. The same happened with Mailgun and others, they all add headers.
Currently I am creating Gmail accounts and sending via SMTP, but Google blocks me for no reason and only allows to send 100 emails a day per account. Also I can only create few emails using the same IP address/phone, so I was forced to use anonymous proxies and fake Chinese phones. Now I am fighting a war on two fronts.
An email can be blocked by three parameters: IP address, domain, and email address.
It will be terrific if I can set up my own Postfix server at a VPS that auto-rotates the IP address. Even better if I can simulate "gmail.com", to avoid purchasing a new domain every day.
All the intents to create what I call "the ultimate sender" just either reach the spam folder or add unwanted headers making it too easy to block. I feel exhausted. I hit a knowledge barrier here.
I know I am crossing to the dark side, but this is for a very good cause. Thousands count on this service as their only source of unbiased news, social network and to feel part of the 21st century.
Can you please help me implementing "the ultimate sender", or pointing to another solution that I may be missing?
My friend, do you remember what made Hillary Clinton lose the last elections to Trump?
It was the "mail" affair. And what was it? People discovered she shared confidential information through a non-official, non-governmental email account (i.e., she used some Gmail, Yahoo or another of a kind). Until here, nothing new with direct relation to your matters. But there is an small particularity on this history, and this can put, maybe not a solution, but maybe a light on a new path you could follow: Clinton actually never sent those emails; the email account she used had the password shared and the communication between people (Clinton-someone) occurred only using the drafts of the account.
How? One side logs in and accesses the drafts folder. There he/she reads the last message and edits it, cutting and writing new data - then save the draft message. On the next turn, the other side of the communication line logs in and do the same. And so forth, so never really sending those messages, but instead just updating the drafts (this "Hillary" method does schooled people... Dilma Rousseff, impeached ex-president of Brazil, actually did this method down there in Brazil too).
So, maybe if you could establish a pact with your user that he/she doesn't delete the account's password, you could pass those information by this method - without "really" exchanging emails. Maybe a "parent" email account (some that could reset a lost password) could be useful too.
Alternative: aren't you able to contract a regular HTTP webserver? You could rely on FTP to publish data to your user, he/she asks for it and you publish a page with that content.
Salvi, have you tried something with Telnet? OK, we are talking here about a text-only environment, but if nothing more would rest in the future, this could be better than nothing. Maybe you could implement a podcast-like, or push-like service based on it. Look what people do with it with references to your walk on the dark side...