SMTP Status 252 : The user account appears to be valid but could not be verified, however the server will try do deliver the message. There are sometimes circumstances where an email address appears to be valid but cannot be verified as definitely valid during the SMTP session between the sending server (your server) and the next server to accept your message. This can happen for example in very large corporation where the first email receiving server might only be an email exchanger server, a gateway server to the eventual server which holds the user mailboxes and which can verify if the intended recipient exists in that organization. When this happens the gateway server will reply with an SMTP Error 252 telling your sending server that it cannot verify the user part of the email address, that the domain part is OK, and that it will forward your email to a server which can do the checking and eventually deliver to the user mailbox if it exists.

Related posts:

1. 251 – User not local will forward (also called SMTP Error 2.5.1) SMTP Status 251 : The email account is not local...
2. 450 – Requested action not taken – The mailbox was unavailable at the remote end. A secondary SMTP error code may follow “450” to refine the reason for the failure to transmit the message, e.g. “SMTP Error 450 (also called SMTP Error 4.5.0) SMTP Error 450 : The server could not access the...
3. 446 – The maximum hop count was exceeded for the message (also called SMTP Error 4.4.6) SMTP Error 446 : The maximum hop count was exceeded...
4. 421 – <Server name> Service not available – the sending email program should try again later (also called SMTP Error 4.2.1) SMTP Error 421 : The Mail transfer service is unavailable...
5. 447 – Your outgoing message timed out. (also called SMTP Error 4.4.7) SMTP Error 447 : Your outgoing message timed out because...

Related posts brought to you by Yet Another Related Posts Plugin.