AddFilters adds RawInterface filters to the context.

GetTestable returns a testable extension interface, or nil if one is not available.

Raw pulls the raw mail service implementation from context or nil if it wasn't set.

Send sends an e-mail message.

SendToAdmins sends an e-mail message to application administrators.

Set sets the mail service in this context.

SetFactory sets the function to produce mail.RawInterface instances, as returned by the Get method.

Attachment is a mimic of https://godoc.org/google.golang.org/appengine/mail#Attachment It's provided here for convenience, and is compile-time checked to be identical.

Message is a mimic of https://godoc.org/google.golang.org/appengine/mail#Message It's provided here for convenience, and is init-time checked to be identical (not statically because []Attachement prevents static casting).

TestMessage is the message struct which will be returned from SentMessages.

RawInterface is the interface for all of the mail methods.

Testable is the interface for mail service implementations which are able to be tested (like impl/memory).

Factory is the function signature for factory methods compatible with SetFactory.

Filter is the function signature for a filter mail implementation.