All SMTP servers basically work this way. This can be done using the freeware PuTTY.
Telnet to server & port: (bold types are user input)
220 BY2NAM03FT048.mail.protection.outlook.com Microsoft ESMTP MAIL Service ready at Wed, 3 Oct 2018 23:54:21 +0000 ehlo 500 5.3.3 Unrecognized command '????' [BY2NAM03FT048.eop-NAM03.prod.protection.outlook.com] ehlo 250-BY2NAM03FT048.mail.protection.outlook.com Hello [69.60.23.131] 250-SIZE 157286400 250-PIPELINING 250-DSN 250-ENHANCEDSTATUSCODES 250-STARTTLS 250-8BITMIME 250-BINARYMIME 250-CHUNKING 250 SMTPUTF8 mail from:<test@mafia.com> 250 2.1.0 Sender OK rcpt to:<timlyg@yahoo.com> 250 2.1.5 Recipient OK data 354 Please start mail input. subject: This is the Subject Line.
this is just a test . 250 Mail queued for delivery. quit
Advanced:
For authentication, after establishing telnet connection and entered two "ehlo" commands, use the command: auth login
334 VXNlcm5hbWU6; will prompt username input, enter base64 encoded username, which is usually the full email address.
334 UGFzc3dvcmQ6; is prompted then for password, enter base64 encoded password.
The rest is the same as above.
Problem: When a user is given a shared mailbox, that mailbox should automatically appear in the user's Outlook client right under the user's folder in the left panel, within a couple of hours if not minutes. But some users never see this happening, and if I add this folder manually via Account settings > More Settings > Advanced > Add Mailboxes > name of mailbox, it will usually prompt for username/password again but will keep popping such prompt as if no valid credentials are entered even when the input is correct, or, the folder will show up but clicking it will only show further error about Exchange server problem. There are similar solutions about this but it never works on my case. They were talking about turning off / on cache, uncheck / check download shared folders, etc.
Though I'm curious and have yet read the Statement, I do think Keller's could take his own medicine on his speech act criticism. That his concern is or doesn't like what the statement is doing in spite of the fact that he could agree what it's saying.
Keller is essentially questioning the motive of those evangelicals, which included John MacArthur, James White, etc. That in itself is a problem, the trust is lacking. I am almost convinced that Keller thought his movement was the only evangelical movement that focuses on social justice and thus was jealous of those who claim to be on the same page, jealous enough to criticize them.
Interestingly, I recall a very recent conversation I had with Drew, a former Redeemer pastoral staff. I asked him why Redeemer appears to treat Christians as outsiders while being very friendly to "seekers", to which his only response was "it's not about all of that, it's about what's Biblical".
Ah...1 Corinthians 1:12 never gets old. At the end of the day, it's about who pride himself of being better at doing both social justice and the Gospel.