SMTP 354 Start Mail Input vs 452 Insufficient Storage
SMTP 354 (Start Mail Input) is a 3xx Positive Intermediate response, while 452 (Insufficient Storage) is a 4xx Transient Negative response. 354 indicates that the server is ready to receive the message body. The client should begin sending the email content (headers and body) and terminate with a single line containing only a period (CRLF.CRLF). In contrast, 452 means that the requested action was not taken because the server has insufficient system storage. The server cannot accept more mail until storage is freed.
Description
The server is ready to receive the message body. The client should begin sending the email content (headers and body) and terminate with a single line containing only a period (CRLF.CRLF).
When You See It
After sending the DATA command. The server is now waiting for you to type or stream the email message, ending with a dot on its own line.
How to Fix
Send your message content followed by a line with just a period (.) to signal the end. If you get an error after this, check that your message does not contain a bare period on a line by itself within the body.
Description
The requested action was not taken because the server has insufficient system storage. The server cannot accept more mail until storage is freed.
When You See It
When the mail server's disk is full or the recipient's mailbox has exceeded its storage quota. The server cannot store additional messages.
How to Fix
If you are the sender, retry later after the recipient frees up space. If you manage the server, clear disk space, increase quotas, or archive old messages.
Key Differences
354 is a 3xx Positive Intermediate response, while 452 is a 4xx Transient Negative response.
SMTP 354: The server is ready to receive the message body. The client should begin sending the email content (headers and body) and terminate with a single line containing only a period (CRLF.CRLF).
SMTP 452: The requested action was not taken because the server has insufficient system storage. The server cannot accept more mail until storage is freed.
You encounter 354 when after sending the DATA command. The server is now waiting for you to type or stream the email message, ending with a dot on its own line.
You encounter 452 when when the mail server's disk is full or the recipient's mailbox has exceeded its storage quota. The server cannot store additional messages.
When to Use Which
For 354 (Start Mail Input): Send your message content followed by a line with just a period (.) to signal the end. If you get an error after this, check that your message does not contain a bare period on a line by itself within the body. For 452 (Insufficient Storage): If you are the sender, retry later after the recipient frees up space. If you manage the server, clear disk space, increase quotas, or archive old messages.