iphone "invalid recipient address" problem
 

I have a "cannot send mail - One of the recipient addresses was invalid" error when attempting to send email from iphone. I have no problem receiving emails and synchronizing to all my folders in fastmail with IMAP.

My outgoing amil server was set as
SMTP host name = mail.messagingengine.com
SSL = on
port = 587

Can someone help? I tried to browse other's sent mail problem but they all seemed to have slightly different issues...

Well, the reason may well be that recipient address is invalid:) Did you try to send email to the very same address using some other method (not iphone)? Did you ever send email to this address successfully?

I was able to send to the same address using the yahoo POP mail set up on my iphone so the problem is with my fastmail set up on the iphone.

If it's a Fastmail.FM issue, it most likely belongs int he Fastmail current issues forum. I'm sure a moderator will move.

Is this problem is only happening with iPhone (i.e. you can email this same person from the Fastmail web interface from a computer)? Also are you typing this email address in manually on the iPhone or is it coming out of an address book? If you are typing it in manually, I would double check the spelling and make sure everything is right (the spellings, make sure it's not a comma where it's supposed to be a period).

I appreciate you asking but the recipient email address is correct. No typo. I have two email accounts set up on the iphone, yahoo mail can send but fastmail cannot.

On the SMTP settings screen on the iPhone, did you set the Authentication to "Password" and input your user name and password? (These would be the same as your login for the inbound mail server.)

[Moderator:] Thread to the "Fastmail.FM Help and Current Issues" Forum.

Welcome to the EMD Forums szla :)

"On the SMTP settings screen on the iPhone, did you set the Authentication to "Password" and input your user name and password? "
Authentication is set to "password". Currently User Name and Password is left empty because I get another error when I filled out those two fields. The error says "Cannot send mail - The user name or password for "SMTP:myUserName@mail.messagingengine.com" is incorrect."

In the username field, try entering your entire email address as your username. ie. someusername (AT) fastmail dot fm.

That's what I did.

Sorry, I didn't read the original post thoroughly. If ssl is enabled, you should be using port 465. Can you check if thats the problem here? If you would like to continue with port 587, disable SSL. Using SSL is recommend though.

Thanks kurianja. I changed the port and got the same recipient address invalid message.

If the iPhone mail client behaves like the Mac mail client, you can use port 587 with the SSL box checked. In this case, it will use the STARTTLS command to establish an encrypted session.

Yes, that's correct placebo. TLS on port 587 is fine, and supported.

I wonder if the issue is that the iphone isn't setting the envelope FROM address to a fully qualified user@domain. We recently (as in, today) started blocking all emails without a fully qualified sender or recipient on the frontend servers the same as we already do on the MXes

(it was part of a "standardise our configs more" push that also sees our MXes accepting opportunistic TLS encryption from sites that want it, so more of the email we receive comes across the wire encrypted)

I have been struggling with the very same problem, combining a Fastmail account and Apple Mail on the iPhone. Since a couple of days I cannot send mail from the iPhone whereas sending from Fastmail webmail or Fastmail via POP account on the iMac is no problem.

Even if I send a test message from the iPhone to one of my own Fastmail accounts I get silly complaints about wrong account name or password from my IMAP FM OUT account, even though I do not use Imap on the iPhone nor on the iMac. That should qualify as a fully qualified user@domain. Receiving mail on the iPhone works. Puzzling.