Among all SMTP reply messages, error 550 is surely the most common.
It generally comes with a side-message like "550 Requested action not taken: mailbox unavailable" or "550 5 2 1 mail from refused spam site".
This allows for another mail server to communicate with yours over smtp since that other server is basically just running through the message dialog we worked through earlier while telneted into the host.
Click Apply to save the changes and for giggles go ahead and stop (disable) and start (enable) the connector.
Of course the best practice here is not simply to erase the address that provokes a 550 error code, but to replace it with a new one whenever possible. If you have another way to contact your user - a phone number, Twitter, Skype...
- just send him a line to apprise him that his current email account is wrong, and to ask him a functioning one.
I am currently doing a website using PHP and the Code Igniter framework.
Relaying occurs when an email message is sent to an email address whose domain (the name after the @ symbol, such as adatum.com) is not processed by the Simple Mail Transfer Protocol (SMTP) or outgoing server that the sender is requesting to deliver the message.Some ISPs might not return an error message when they detect outgoing messages as unsolicited commercial email.In these cases, your message might appear to be sent normally — it leaves your Outlook Outbox and appears in your Sent Items — but it's never actually delivered to the recipient.Check if your sending IP is on any spam lists, search for “spam database lookup”. Ensure you have no virus infected machines on your network that are being used to send spam through your mail server. Ensure you have no exploitable web scripts on your web servers that could be abused to send spam.You are looking for any 3rd party lists that may have received spam from your mail server. The most commonly used one is PHP contact scripts which spammers use to abuse the PHP “mail()” function, giving them free reign to send what they want. Make sure any ‘opt-in’ newsletters contain an ‘opt-out’ link to be certain users can easily unsubscribe.If your IP address is on any of these block lists, please make a removal request as soon as possible, once removed please retry sending your mail. Ensure your mail server is not open relay, search for “Email Open Relay Tester” and choose from any number of testers. If your internet line is provided by DSL or Cable that shares IP’s with residential users, please ensure your mail server sends to your ISP’s smart host instead of direct to the internet. If the problem persists, please contact the recipient by other means and request that your email address be added to their Symantec Cloud approved senders list.