I have a free license, but when I try to send anything it's "returned to sender"

I can send e-mails to and from this same address just fine on my iPhone Mail client, so it has to be eM. No idea what’s going on.

What is the exact error for the “return to sender”?

This message was created automatically by mail delivery software.

A message that you sent could not be delivered to one or more of its

recipients. This is a permanent error. The following address(es) failed:


host eig-east.smtp.a.cloudfilter.net []

SMTP error from remote mail server after end of data:

550 is listed on Cloudmark CSI-Global. Please

This does not appear to be an eM Client problem, as it is just reflecting the error YOUR host has sent to you. More than likely the email address you are sending to is blacklisted on the host system. Time to contact your host and open a ticket.

The iPhone Mail client is sending messages to/from this address just fine though–that’s why I’m posting here. I can successfully send messages from tiffany@tifforelie dot com (the address I’m having issues with) to the address I shared above (kuliana116@yahoo dot com) on my iPhone as well as any other address, but cannot successfully send any messages from tiffany@tifforelie dot com TO any of those same addresses using eM client.

You need to verify the outgoing SMTP server server is the same on the iPhone and eM Client. If one works and the other doesn’t you could have different outgoing SMTP settings between the two devices.

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It’s so bizarre. The IMAP and SMTP settings are identical to what I have set up on my phone, and even when I run the diagnostic in the eM client, both IMAP and SMTP get the green check. Yet when I try to send a message to any address, within seconds I receive the “returned to sender” message.

What is the smtp server setting you have ?

Also can you send yourself an email ?

I’ve tested with 2 different smtp server settings, both of which work on my iphone:


I am able to send myself an e-mail using both, but I am unable to send anything without “returned to sender” to any other address.

I’ve tested with 2 different smtp server settings, both of which work on my iphone:


As both SMTP address’s above send ok and are not returned on your iPhone, are you using any VPN’s or Proxies on your computer ? Could be an IP address problem on your computer that is maybe blacklisted and your computer IP address is maybe blocked and the email is then returned.

Can you send email to these same or any email address’s from any other email clients with the same SMTP Server settings on your computer ? Is the problem only with eM Client or any email client ?.

Also what are your SMTP Server Port and Security Policy in eM Client ?

Lastly is the sender email address and reply address showing the same in eM Client as in your iPhone ? As “if eg: it’s a different sending email address than your normal reply address” in eM Client that could be why emails are being returned in eM Client but not on your iPhone, as the receiving server might think it’s suspicious.