452
SMTP
452 Insufficient Storage
The requested action was not taken because the server has insufficient system storage. The server cannot accept more mail until storage is freed.
このコードが表示される場合
When the mail server's disk is full or the recipient's mailbox has exceeded its storage quota. The server cannot store additional messages.
解決方法
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.
比較対象
ガイド
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Diagnosing Email Bounces: Soft (4xx) vs Hard (5xx)
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DMARC Reporting: Analyzing Aggregate and Forensic Reports
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Email Feedback Loops (FBL): Processing Spam Complaints
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DNS Record Types Explained: A, AAAA, CNAME, MX, TXT, and Beyond
DNS & Networking
TCP Three-Way Handshake and Connection Lifecycle
DNS & Networking
RFC 5321: SMTP Protocol Deep Dive
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RFC 959: FTP Protocol Deep Dive
Protocol Deep Dives
TLS 1.3: Faster, Simpler, More Secure
Protocol Deep Dives
デバッグシナリオ
用語集
Status Code
Media Type (MIME Type)
TLS Handshake
TLS Certificate (SSL Certificate)
Cipher Suite
Authentication
TCP/IP
Three-Way Handshake
Port Number
Firewall
IPv6
Exponential Backoff
Error Code Mapping
Poison Message
Request-Response Model
RFC (Request for Comments)
IANA (Internet Assigned Numbers Authority)
Message Framing
Connection-Oriented
Text vs Binary Protocol
MX Record
PTR Record
SMTP Relay
SPF, DKIM, and DMARC
Bounce Rate (Email)
Email Deliverability
MTA (Mail Transfer Agent)
SMTP Pipelining
Greylisting
Backscatter
Envelope vs Header
STARTTLS
SMTP Authentication (SMTP AUTH)
Open Relay
Email Queue
MIME Multipart
ARC (Authenticated Received Chain)
BIMI (Brand Indicators for Message Identification)
DSN (Delivery Status Notification)
Email Header Injection
SMTP Enhanced Status Codes
MDN (Message Disposition Notification)
MIME Type
TLS Versions
TLS 1.3
Certificate Authority (CA)
Forward Secrecy (PFS)
SNI (Server Name Indication)
TLS Session Resumption
Key Exchange
PKI (Public Key Infrastructure)