Diagnostic-Code: smtp; 550 5.7.1 Command rejected

[Wayne_Rowlands]

I have the SAME problem. I get error code 550. This is totally not right. This is an HP problem that needs to be fixed. The fixes recommended are simply complicatesd and simply DO NOT workl. What the Heck? Terrible.

[Jeet_singh]

@Wayne_Rowlands,

Thank you for posting your query on HP Community,

Are you using a dual band router?

Note: HP Printers do not work or connect to 5Ghz networks. If you are using a dual band router, please give different names to 2.4Ghz and 5 Ghz networks and connect the printer to the 2.4Ghz network.

Recommend you assign a manual IP and DNS to the printer and check if it resolves the issue you are facing. 

• Obtain the IP address of the printer (which can found by pressing the “wireless” icon on the printer control panel)
• Enter the IP address on the web browser (Ex: chrome, IE) to enter the printer EWS page.
• Go to the “Network” tab, click on “Wireless (802.11) then click on “Network address (IPV4)
• Click on the radio button which says “Manual IP” and then click “Suggest a manual IP address” to give a manual IP address to your printer.
• Click on the radio button which says “Manual DNS server” and under manual preferred type 8.8.8.8 and under manual alternate type 8.8.4.4 (This is Google DNS server address)

If your HP ePrint job fails, confirm the network connection is functioning and check ePrint requirements.​

1. Restart the printer.

2. Print a test page from a device on the same local network, and then respond to any messages that display.

3. Make sure the email subject line is filled out, your printer email address is correct, and you have less than ten compatible attachments.

For more detailed steps follow this document "HP Printers - HP ePrint Job Does Not Print"

Let me know if this helps you fix this issue.

If this helps, mark this post as an accepted solution so that it can benefit others.

Cheers​​​​