SMTP: Relay Server Codes

Code Meaning
200 (nonstandard success response, see rfc876)
211 System status, or system help reply
214 Help message
220 Service ready
221 Service closing transmission channel
250 Requested mail action okay, completed
251 User not local; will forward to
354 Start mail input; end with .
421 Service not available, closing transmission channel
450 Requested mail action not taken: mailbox unavailable
451 Requested action aborted: local error in processing
452 Requested action not taken: insufficient system storage
500 Syntax error, command unrecognised
501 Syntax error in parameters or arguments
502 Command not implemented
503 Bad sequence of commands
504 Command parameter not implemented
521 does not accept mail (see rfc1846)
530 Access denied (???a Sendmailism)
550 Requested action not taken: mailbox unavailable
551 User not local; please try
552 Requested mail action aborted: exceeded storage allocation
553 Requested action not taken: mailbox name not allowed
554 Transaction failed
Reply codes grouped by command
Command Code Description
connect
220 Service ready
421 Service not available, closing transmission channel
HELO
250 Requested mail action okay, completed
500 Syntax error, command unrecognised
501 Syntax error in parameters or arguments
504 Command parameter not implemented
521 does not accept mail [rfc1846]
421 Service not available, closing transmission channel
EHLO
250 Requested mail action okay, completed
550 Not implemented
500 Syntax error, command unrecognised
501 Syntax error in parameters or arguments
504 Command parameter not implemented
421 Service not available, closing transmission channel
MAIL
250 Requested mail action okay, completed
552 Requested mail action aborted: exceeded storage allocation
451 Requested action aborted: local error in processing
452 Requested action not taken: insufficient system storage
500 Syntax error, command unrecognised
501 Syntax error in parameters or arguments
421 Service not available, closing transmission channel
RCPT
250 Requested mail action okay, completed
251 User not local; will forward to
550 Requested action not taken: mailbox unavailable
551 User not local; please try
552 Requested mail action aborted: exceeded storage allocation
553 Requested action not taken: mailbox name not allowed
450 Requested mail action not taken: mailbox unavailable
451 Requested action aborted: local error in processing
452 Requested action not taken: insufficient system storage
500 Syntax error, command unrecognised
501 Syntax error in parameters or arguments
503 Bad sequence of commands
521 does not accept mail [rfc1846]
421 Service not available, closing transmission channel
DATA
354 Start mail input; end with .
451 Requested action aborted: local error in processing
554 Transaction failed
500 Syntax error, command unrecognised
501 Syntax error in parameters or arguments
503 Bad sequence of commands
421 Service not available, closing transmission channel
received data
250 Requested mail action okay, completed
552 Requested mail action aborted: exceeded storage allocation
554 Transaction failed
451 Requested action aborted: local error in processing
452 Requested action not taken: insufficient system storage
RSET
200 (nonstandard success response, see rfc876)
250 Requested mail action okay, completed
500 Syntax error, command unrecognised
501 Syntax error in parameters or arguments
504 Command parameter not implemented
421 Service not available, closing transmission channel
SEND
250 Requested mail action okay, completed
552 Requested mail action aborted: exceeded storage allocation
451 Requested action aborted: local error in processing
452 Requested action not taken: insufficient system storage
500 Syntax error, command unrecognised
501 Syntax error in parameters or arguments
502 Command not implemented
421 Service not available, closing transmission channel
SOML
250 Requested mail action okay, completed
552 Requested mail action aborted: exceeded storage allocation
451 Requested action aborted: local error in processing
452 Requested action not taken: insufficient system storage
500 Syntax error, command unrecognised
501 Syntax error in parameters or arguments
502 Command not implemented
421 Service not available, closing transmission channel
SAML
250 Requested mail action okay, completed
552 Requested mail action aborted: exceeded storage allocation
451 Requested action aborted: local error in processing
452 Requested action not taken: insufficient system storage
500 Syntax error, command unrecognised
501 Syntax error in parameters or arguments
502 Command not implemented
421 Service not available, closing transmission channel
VRFY
250 Requested mail action okay, completed
251 User not local; will forward to
550 Requested action not taken: mailbox unavailable
551 User not local; please try
553 Requested action not taken: mailbox name not allowed
500 Syntax error, command unrecognised
501 Syntax error in parameters or arguments
502 Command not implemented
504 Command parameter not implemented
421 Service not available, closing transmission channel
EXPN
250 Requested mail action okay, completed
550 Requested action not taken: mailbox unavailable
500 Syntax error, command unrecognised
501 Syntax error in parameters or arguments
502 Command not implemented
504 Command parameter not implemented
421 Service not available, closing transmission channel
HELP
211 System status, or system help reply
214 Help message
500 Syntax error, command unrecognised
501 Syntax error in parameters or arguments
502 Command not implemented
504 Command parameter not implemented
421 Service not available, closing transmission channel
NOOP
200 (nonstandard success response, see rfc876)
250 Requested mail action okay, completed
500 Syntax error, command unrecognised
421 Service not available, closing transmission channel
QUIT
221 Service closing transmission channel
500 Syntax error, command unrecognised
TURN
250 Requested mail action okay, completed
502 Command not implemented
500 Syntax error, command unrecognised
503 Bad sequence of commands