twisted.mail.relaymanager.MXCalculator
class documentationtwisted.mail.relaymanager
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A utility for looking up mail exchange hosts and tracking whether they are working or not.
Instance Variable | clock | A reactor which will be used to schedule timeouts. (type: IReactorTime
provider) |
Instance Variable | resolver | A resolver. (type: IResolver ) |
Instance Variable | badMXs | A mapping of non-functioning mail exchange hostname to time at which
another attempt at contacting it may be made. (type: dict
mapping bytes
to float ) |
Instance Variable | timeOutBadMX | Period in seconds between attempts to contact a non-functioning mail
exchange host. (type: int ) |
Instance Variable | fallbackToDomain | A flag indicating whether to attempt to use the hostname directly when no
mail exchange can be found (True ) or not (False ). (type: bool ) |
Method | __init__ | |
Method | markBad | Record that a mail exchange host is not currently functioning. |
Method | markGood | Record that a mail exchange host is functioning. |
Method | getMX | Find the name of a host that acts as a mail exchange server for a domain. |
Method | _filterRecords | Organize the records of a DNS response by record name. |
Method | _cbMX | Try to find the mail exchange host for a domain from the given DNS records. |
Method | _ebMX | Attempt to use the name of the domain directly when mail exchange lookup fails. |
int
)
True
) or not (False
). (type: bool
)
Parameters | A resolver. | |
clock | A reactor which will be used to schedule timeouts. (type: IReactorTime
provider or None ) |
Record that a mail exchange host is not currently functioning.
Parameters | mx | The hostname of a mail exchange host. (type: bytes ) |
Record that a mail exchange host is functioning.
Parameters | mx | The hostname of a mail exchange host. (type: bytes ) |
Find the name of a host that acts as a mail exchange server for a domain.
Parameters | domain | A domain name. (type: bytes ) |
maximumCanonicalChainLength | The maximum number of unique canonical name records to follow while looking
up the mail exchange host. (type: int ) | |
Returns | A deferred which succeeds with the MX record for the mail exchange server
for the domain or fails if none can be found. (type: Deferred
which successfully fires with Record_MX ) |
Organize the records of a DNS response by record name.
Parameters | records | Answer resource records, authority resource records and additional resource
records. (type: 3-tuple
of (0) list
of RRHeader , (1)
list
of RRHeader , (2)
list
of RRHeader ) |
Returns | A mapping of record name to record payload. (type: dict
mapping bytes
to list
of IRecord
provider) |
Try to find the mail exchange host for a domain from the given DNS records.
This will attempt to resolve canonical name record results. It can recognize loops and will give up on non-cyclic chains after a specified number of lookups.
Parameters | answers | A mapping of record name to record payload. (type: dict
mapping bytes
to list
of IRecord
provider) |
domain | A domain name. (type: bytes ) | |
cnamesLeft | The number of unique canonical name records left to follow while looking up
the mail exchange host. (type: int ) | |
Returns | An MX record for the mail exchange host or a failure if one cannot be
found. (type: Record_MX or Failure ) |
Attempt to use the name of the domain directly when mail exchange lookup fails.
Parameters | failure | The reason for the lookup failure. (type: Failure ) |
domain | The domain name. (type: bytes ) | |
Returns | An MX record for the domain or a failure if the fallback to domain option
is not in effect and an error, other than not finding an MX record,
occurred during lookup. (type: Record_MX or Failure ) | |
Raises | IOError | When no MX record could be found and the fallback to domain option is not in effect. |
DNSLookupError | When no MX record could be found and the fallback to domain option is in effect but no address for the domain could be found. |