On this page:
communicator
connect-to-server
disconnect-from-server
authenticate/  plain-text
get-mailbox-status
get-message/  complete
get-message/  headers
get-message/  body
delete-message
get-unique-id/  single
get-unique-id/  all
make-desired-header
extract-desired-headers
11.1 Exceptions
pop3
cannot-connect
username-rejected
password-rejected
not-ready-for-transaction
not-given-headers
illegal-message-number
cannot-delete-message
disconnect-not-quiet
malformed-server-response
11.2 Example Session
11.3 POP3 Unit
[email protected]
11.4 POP3 Signature
pop3^

11 POP3: Reading Mail

 (require net/pop3) package: net-lib
The net/pop3 module provides tools for the Post Office Protocol version 3 [RFC977].

struct

(struct communicator (sender receiver server port state)
    #:extra-constructor-name make-communicator)
  sender : output-port?
  receiver : input-port?
  server : string?
  port : (integer-in 0 65535)
  state : (one-of/c 'disconnected 'authorization 'transaction)
Once a connection to a POP-3 server has been established, its state is stored in a communicator instance, and other procedures take communicator instances as an argument.

procedure

(connect-to-server server [port-number])  communicator?

  server : string?
  port-number : (integer-in 0 65535) = 110
Connects to server at port-number.

procedure

(disconnect-from-server communicator)  void?

  communicator : communicator?
Disconnects communicator from the server, and sets communicator’s state to 'disconnected.

procedure

(authenticate/plain-text user    
  passwd    
  communicator)  void?
  user : string?
  passwd : string?
  communicator : communicator?
Authenticates using user and passwd. If authentication is successful, communicator’s state is set to 'transaction.

Returns the number of messages and the number of octets in the mailbox.

procedure

(get-message/complete communicator 
  message-number) 
  
(listof string?) (listof string?)
  communicator : communicator?
  message-number : exact-integer?
Given a message number, returns a list of message-header lines and list of message-body lines.

procedure

(get-message/headers communicator 
  message-number) 
  
(listof string?) (listof string?)
  communicator : communicator?
  message-number : exact-integer?
Given a message number, returns a list of message-header lines.

procedure

(get-message/body communicator 
  message-number) 
  
(listof string?) (listof string?)
  communicator : communicator?
  message-number : exact-integer?
Given a message number, returns a list of message-body lines.

procedure

(delete-message communicator    
  message-number)  void?
  communicator : communicator?
  message-number : exact-integer?
Deletes the specified message.

procedure

(get-unique-id/single communicator    
  message-number)  string?
  communicator : communicator?
  message-number : exact-integer?
Gets the server’s unique id for a particular message.

procedure

(get-unique-id/all communicator)

  (listof (cons/c exact-integer? string?))
  communicator : communicator?
Gets a list of unique id’s from the server for all the messages in the mailbox. The car of each item in the result list is the message number, and the cdr of each item is the message’s id.

procedure

(make-desired-header tag-string)  regexp?

  tag-string : string?
Takes a header field’s tag and returns a regexp to match the field

procedure

(extract-desired-headers header desireds)  (listof string?)

  header : (listof string?)
  desireds : (listof regexp?)
Given a list of header lines and of desired regexps, returns the header lines that match any of the desireds.

11.1 Exceptions

struct

(struct pop3 exn ()
    #:extra-constructor-name make-pop3)
The supertype of all POP3 exceptions.

struct

(struct cannot-connect pop3 ()
    #:extra-constructor-name make-cannot-connect)
Raised when a connection to a server cannot be established.

struct

(struct username-rejected pop3 ()
    #:extra-constructor-name make-username-rejected)
Raised if the username is rejected.

struct

(struct password-rejected pop3 ()
    #:extra-constructor-name make-password-rejected)
Raised if the password is rejected.

struct

(struct not-ready-for-transaction pop3 (communicator)
    #:extra-constructor-name make-not-ready-for-transaction)
  communicator : communicator?
Raised when the communicator is not in transaction mode.

struct

(struct not-given-headers pop3 (communicator message)
    #:extra-constructor-name make-not-given-headers)
  communicator : communicator?
  message : exact-integer?
Raised when the server does not respond with headers for a message as requested.

struct

(struct illegal-message-number pop3 (communicator message)
    #:extra-constructor-name make-illegal-message-number)
  communicator : communicator?
  message : exact-integer?
Raised when the client specifies an illegal message number.

struct

(struct cannot-delete-message exn (communicator message)
    #:extra-constructor-name make-cannot-delete-message)
  communicator : communicator?
  message : exact-integer?
Raised when the server is unable to delete a message.

struct

(struct disconnect-not-quiet pop3 (communicator)
    #:extra-constructor-name make-disconnect-not-quiet)
  communicator : communicator?
Raised when the server does not gracefully disconnect.

struct

(struct malformed-server-response pop3 (communicator)
    #:extra-constructor-name make-malformed-server-response)
  communicator : communicator?
Raised when the server produces a malformed response.

11.2 Example Session

> (require net/pop3)
> (define c (connect-to-server "foo.bar.com"))
> (authenticate/plain-text "bob" "********" c)
> (get-mailbox-status c)
196
816400
> (get-message/headers c 100)
("Date: Thu, 6 Nov 1997 12:34:18 -0600 (CST)"
 "Message-Id: <[email protected]>"
 "From: Alice <[email protected]>"
 ....
 "Status: RO")
> (get-message/complete  c 100)
("Date: Thu, 6 Nov 1997 12:34:18 -0600 (CST)"
 "Message-Id: <[email protected]>"
 "From: Alice <[email protected]>"
 ....
 "Status: RO")
("some body" "text" "goes" "." "here" "." "")
> (get-unique-id/single c 205)
no message numbered 205 available for unique id
> (list-tail (get-unique-id/all c) 194)
((195 . "e24d13c7ef050000") (196 . "3ad2767070050000"))
> (get-unique-id/single c 196)
"3ad2767070050000"
> (disconnect-from-server c)

11.3 POP3 Unit

[email protected] and pop3^ are deprecated. They exist for backward-compatibility and will likely be removed in the future. New code should use the net/pop3 module.

 (require net/pop3-unit) package: compatibility-lib

value

[email protected] : unit?

Imports nothing, exports pop3^.

11.4 POP3 Signature

 (require net/pop3-sig) package: compatibility-lib

signature

pop3^ : signature

Includes everything exported by the net/pop3 module.