211 System status or system help reply
- A help message for human reader follows. (Information on how to use the receiver or the meaning of a particular non-standard command)
<domain> Service ready
Confirming the connection to your ISP mail server.
<domain> Service closing transmission channel
Requested mail action
Your ISP mail server have successfully executes a command and the DNS is reporting a positive delivery.
User not local, will
forward to <forward-path>
Start mail input and end with <CRLF> <CRLF>
Service not available, closing transmission channel
- This may be a reply to any command if the service knows it must shut down.
450 Requested mail actions not taken: mailbox unavailable - Your ISP mail server indicates that an email address does not exist or the mailbox is busy.
It could be the network connection went down while sending, or it could also happen if the remote mail server does not want to
accept mail from your for some reason i.e. (IP address, From address, Recipient, etc.)
Requested actions aborted: local error in processing
Requested actions not
taken: insufficient system storage
452 too many messages' error - Some mail servers have the option to reduce the number of concurrent connection and also the number of messages sent per connection.
If you have a lot of messages queued up it could go over the max number of messages per connection.
To see if this is the case you can try submitting only a few messages to that domain at a time and then keep increasing the number until you find the maximum number accepted by the server.
Syntax error, command
in parameters or arguments -
Indicates possible poor (noisy dialup) or an intermittent drop in network line connection that caused your mail client to send erroneous command to the mail server.
Command not implemented
Indicates that your ISP mail server did not recognized a command sent.
503 Server encountered bad sequence of commands - Indicates (probable) that your ISP mail server did not recognized a command sent that is erroneous.
Some temporary event prevents the successful sending of the message or an intermittent drop in network line connection that caused your mail client to send erroneous command and sending in the future may be successful.
504 Command parameter not implemented - Indicates that your ISP mail server did not recognized a command sent.
Access denied (???a Sendmailism)
Requested actions not
taken, mailbox unavailable -
Indicates that your recipient's email address was not recognized by your ISP mail server or (mailbox not found or cannot access it).
Relaying prohibited or
Not local host… not a gateway or
Unable to relay for… or
user’s mailbox unavailable
This address is not allowed or
Requested action not taken: mailbox unavailable
Seems like the setting of the “From Address” are incorrect and/or an attempted was made to deliver but there was a non fatal error and it will be retried and/or some change to the message destination must be made for successful delivery.
User not local, please try <forward-path> or
Invalid Address: Relay request denied -
Indicates that the recipient's email address have changed and your ISP mail server is forwarding it back to you and/or your ISP SMTP mail server does not accept email when neither the sender nor the recipient is a local user--this feature was implemented to protect the mail server from being used by spammers to relay their messages by using another company’s network and computer resources.
Requested mail actions aborted: exceeded storage allocation
ISP mail server indicates, probable overloading from too many messages.
553 Denied. Requested action not taken: mailbox name not allowed or bad command format - (E.g., mailbox syntax incorrect) Some mail servers have the option to reduce the number of concurrent connection and also the number of messages sent per connection.
If you have a lot of messages queued up (being sent) for a domain, it could go over the maximum number of messages per connection and/or some change to the message and/or destination must be made for successful delivery.
Transaction failed or
Too many duplicate messages: Resource
temporarily unavailable -
Indicates (probable) that there is some kind of anti-spam system on the mail server.
572 Relay not authorized or Not local host… not a gateway - Not allowed to send email to recipients outside of your domain. To prevent SPAM many mail server will not allow you to send mail to any ISP SMTP mail server when either the sender or recipient is a local user.
This feature is implemented to protect the mail server from being used by spammers to relay their messages using another company’s network and computer resources. Some mail servers required you to log in before sending messages.
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