ErrLookup › jstedfast/MailKit

jstedfast/MailKit

A cross-platform .NET library for IMAP, POP3, and SMTP. · C# · 365 source files

Analyzed at 9d3859a785 on 2026-09-15. 288 documented errors.

Code / MessageTypeSeverityTags
The SearchOptions.All flag cannot be combined with a…
exception error argument-validation, mailkit, search, conflicting-options
QRESYNC needs to be enabled immediately after…
exception error imap, qresync, invalid-state-transition, mailkit
The Pop3Client has not been authenticated.
exception error pop3, mailkit, authentication, state-error
The folder does not support partial searches.
exception error mailkit, not-supported, search, partial-range
Failed to negotiate authentication method with the proxy…
exception error network, socks5, proxy, authentication
Unexpected response from server
exception error pop3, mailkit, protocol-error, network
No credentials could be found for the POP3 server.
exception error pop3, mailkit, credentials, authentication
Unknown URI scheme.
exception error mailkit, uri, scheme, connection
Failed to connect to
exception error socks5, proxy, connection
Specified argument was out of the range of valid values.
exception error ntlm, argument-out-of-range, mailkit
Value cannot be null. (Parameter 'name')
validation error argument-null, imap, acl, mailkit
The IMAP server does not support the ESEARCH extension.
exception error imap, mailkit, not-supported, esearch, server-capability
The ImapFolder does not support annotations.
exception error imap, mailkit, not-supported, annotations, capability-check
One or more of the uids is invalid.
validation error mailkit, imap, uid, argument-exception
offset
validation error argument-exception, hash, out-of-range, md4
The ANNOTATION search term is not supported by the IMAP…
exception error imap, search, capability-check, annotate
The IMAP server did not return the requested body part.
exception error imap, mailkit, message-not-found, fetch
The uid is invalid.
exception error imap, argument-validation, mailkit, uid
format, args
exception error mailkit, imap, protocol-error, unexpected-token
InvalidChallenge
Challenge contained an invalid nonce.
error_code error sasl, scram, authentication, nonce, security, mailkit
The ImapClient is not connected.
exception error imap, mailkit, connection-state, network
You must enable UTF-8 mode before authenticating.
exception error pop3, utf8, state-machine, mailkit, ordering
IncorrectHash
Server response did not contain the expected hash.
error_code error sasl, digest-md5, authentication, hash
The IMAP command queue is empty.
exception error concurrency, imap, race-condition, threading
The IMAP server did not return the requested message…
exception error imap, message-not-found, mailkit, server-response
HashAlgorithm
validation error csharp, disposed-object, hashing, ntlm
keywords
exception error argument-null, imap, append, mailkit
The IMAP server did not return the requested body part…
exception error imap, message-not-found, mailkit, bodypart
The IMAP server does not support negative partial ranges.
exception error imap, mailkit, not-supported, partial-range, rfc9394
The ImapFolder does not support mod-sequences.
exception error imap, mailkit, not-supported, modseq, condstore, fetch
The POP3 server does not support the STLS extension.
exception error pop3, tls, starttls, mailkit, capability-negotiation
Capabilities cannot be enabled, they may only be disabled.
validation error smtp, capabilities, setter
One or more messages is missing information needed for…
exception error csharp, mailkit, sorting, imessagesummary, fetch-fields
The POP3 server does not support the UIDL extension.
exception error pop3, uidl, uid, capability, mailkit
The set of unique identifiers is too large to fetch with a…
exception error imap, mailkit, not-supported, partial, uid-limit, fetch
The SAVEDATESUPPORTED search term is not supported by the…
exception error imap, search, capability-check, savedate
The IMAP server does not support the Google Mail extensions.
exception error imap, mailkit, gmail, labels, not-supported
The socket is not connected.
validation error smtp, socket, argument-validation, connection
The FILTER search term is not supported by the IMAP server.
exception error imap, search, capability-check, dovecot
The IMAP server does not support the NOTIFY extension.
exception error imap, notify, capability, mailkit
The LOGIN command is disabled.
exception critical imap, login-disabled, tls, authentication, mailkit
index
validation error imap, argument-out-of-range, mailkit, sequence-index
The IMAP server does not support the PARTIAL extension.
exception error imap, mailkit, not-supported, partial-range, server-capability
The POP3 server has unexpectedly disconnected.
exception error pop3, network, disconnection, timeout, mailkit
The SAVEDBEFORE search term is not supported by the IMAP…
exception error imap, search, capability-check, savedate
contentType
exception error mailkit, null-argument, mime, bodystructure
The SmtpClient must be connected before you can…
exception error smtp, mailkit, connection-state, authentication
Cannot search for an empty set of unique identifiers.
validation error mailkit, imap, argument-validation, empty-collection
section
validation error imap, mailkit, null-argument, bodypart
The Pop3Client is already connected.
exception error pop3, mailkit, already-connected, invalid-state
No compatible authentication mechanisms found.
exception error smtp, mailkit, sasl, mechanism-negotiation
count
validation error argument-validation, mailkit, imap, range
Invalid part-specifier in annotation entry.
validation error imap, annotations, format-exception, parser
inputBuffer
validation error argument-exception, null, crypto, transformblock
The FUZZY search term is not supported by the IMAP server.
exception error imap, search, capability-check, fuzzy-search
The IMAP server does not support the METADATA extension.
exception error imap, metadata, unsupported-feature, capability-check
The YOUNGER search term is not supported by the IMAP server.
exception error imap, search, capability-check, within
visitor
exception error null-reference, visitor-pattern, argument-validation, mailkit
The default system proxy does not support
exception error proxy, network, unsupported-scheme
MissingChallenge
Server response did not contain any authentication data.
error_code error sasl, ntlm, authentication, mailkit
MessageNotAccepted
No recipients were accepted.
error_code error smtp, recipients, send, async
No credentials could be found for the IMAP server.
exception error imap, credentials, authentication, mailkit
The OLDER search term is not supported by the IMAP server.
exception error imap, search, capability-check, within
Operation timed out after
exception error network, timeout, socket, mailkit
Indexes and '*' cannot be used while…
exception error imap, mailkit, notify-extension, sequence-numbers
Only message events may be specified when SELECTED or…
exception error imap, notify, rfc5465, validation
The IMAP server has unexpectedly disconnected.
exception critical imap, mailkit, network, connection-dropped, protocol-exception
part
validation error imap, null-argument, mailkit, argument-validation
The IMAP server did not return the requested message.
exception warning imap, message-not-found, race-condition, mailkit
Literal token length
exception error imap, protocol, literal, size-limit
The host address must be an IPv4 or IPv6 address.
validation error socks5, argument, ip-address
The MessageNew event cannot have any parameters for mailbox…
exception error imap, notify, rfc5465, validation
bodyParts
exception error null-reference, constructor, argument-validation, mailkit
Metadata tag does not reference a valid filter.
validation error csharp, mailkit, imap, metadata, search-query
UTF8=ACCEPT needs to be enabled immediately after…
exception error imap, utf8, invalid-state-transition, mailkit
One or more of the indexes are invalid.
validation error pop3, argument-validation, index-out-of-range, mailkit
Failed to resolve host
exception error dns, network, smtp, resolve
The length of the host name must be between 0 and 256…
validation error proxy, argument-validation, configuration, mailkit
inputOffset
validation error argument-exception, crypto, out-of-range, transformblock
outputOffset
validation error argument-exception, crypto, out-of-range, transformblock
SmtpStatusCode.TransactionFailed
No recipients were accepted.
exception error smtp, mailkit, recipient-rejected, transaction-failed
inputCount
validation error argument-exception, crypto, out-of-range, transformblock
Unexpected TAG value in untagged ESEARCH response:
exception error imap, protocol-violation, esearch, server-bug
The host name cannot be empty.
validation error pop3, mailkit, empty-string, argument-validation
Invalid status code returned by the server.
exception error smtp, protocol, status-code, server-reply
One or more annotations does not define any attributes.
validation error imap, argument-validation, annotations, mailkit
The X-GM-MSGID search term is not supported by the IMAP…
exception error imap, gmail, capability-check, not-supported
The SMTP server has unexpectedly disconnected
exception error smtp, mailkit, network, disconnection
Invalid Type message.
exception error ntlm, signature, mailkit
LOGIN does not support SASL-IR.
exception error sasl, login, sasl-ir, mailkit
partSpecifier
exception error mailkit, null-argument, imap, bodystructure
The Pop3Client must be connected before you can…
exception error pop3, mailkit, connection, state-error
Value cannot be null. (Parameter 'rights')
validation error argument-null, imap, acl, mailkit
Value cannot be null.
exception error sasl, argument-null, credentials, mailkit
message
exception error argument-null, event-args, authentication, mailkit
The SAVEDON search term is not supported by the IMAP server.
exception error imap, search, capability-check, savedate
Unexpected greeting from server
exception error pop3, protocol-error, connection, greeting, mailkit
uri
exception error null-reference, argument-validation, mailkit
IncompleteChallenge
Challenge did not contain a salt.
error_code error sasl, scram, authentication, mailkit
MD4
validation error object-disposed, hash, lifetime, md4