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Receiving and Processing Emails

The common process for receiving emails has the following steps:

  1. Retrieve a set of messages from the server.

  2. Process the returned set of messages.

  3. Delete all or some messages, or move them to a specific folder.

Operations expecting a folderPath argument will treat this the following way:

Folder Path Description  Example
NULL

This is interpreted as meaning the <Inbox> folder.
path beginning with / This is interpreted as a path from the mail connections root folder. /Archive/Orders
path not beginning with /

This is interpreted as a relative path to the <Inbox> folder, so translates to /<Inbox>/Archive/Orders.

 Archive/Orders 

The intention of this behavior is to abstract away the fact that <Inbox> has many different names depending on the connection, i.e. IMAP typically uses INBOX, Exchange calls it Inbox, and a German Exchange calls it Posteingang.

Also note that POP3 does not support folders other than <Inbox>. Hence when you specify a POP3 connection, folderPath parameters other than NULL will raise an exception.

Step 1: Retrieving Messages

You can retrieve messages using one of

  • readMessages

  • readMessagesFiltered

Both return an Array of ReceivedMail (see Processing Messages further below).

jmail_operations.png

jmail_read_args.png

Operations

readMessages

Optional: IPgpKeyProvider Implementation

For PGP decryption to work, be sure to register your implementation of IPgpKeyProvider (see Keys and Certificates). If not provided, PGP encrypted messages will still be retrieved, with two attachments that contain the encrypted message information.

Parameter Type Direction Description
connection (25.2) JavaMail Library Reference#Connection in Specify the Connection object defining the mail server connection parameters to use (see Mail Server Connection).
flags (25.2) JavaMail Library Reference#ReadFlags in Specify an instance of ReadFlags to set some mail reading flags.
folderPath String in Specify a path to a folder to read from. See note regarding folder handling.

readMessagesFiltered

Optional: IPgpKeyProvider Implementation

For PGP decryption to work, be sure to register your implementation of IPgpKeyProvider (see Keys and Certificates). If not provided, PGP encrypted messages will still be retrieved, with two attachments that contain the encrypted message information.

Parameter Types Direction Description
connection (25.2) JavaMail Library Reference#Connection in Specify the Connection object defining the mail server connection parameters to use (see Mail Server Connection).
flags (25.2) JavaMail Library Reference#ReadFlags in Specify an instance of ReadFlags (see below).
folderPath String in Specify a path to a folder to read from. See note regarding folder handling.
filter (25.2) JavaMail Library Reference#Filter in Specify an instance of Filter containing the filter criteria.

Types

ReadFlags

Attribute Name Type Description Allowed Values Comment
maxResultCount Integer

Specify a limit for the number of messages to be returned.

If you do not provide a filter as parameter, it makes sense to provide a meaningful limit, as the complete result set will be kept in memory.

 any positive integer

Default is NULL, meaning no limit is imposed.
deleteOnServer Boolean Specify whether successfully read messages will automatically be deleted on the server. true

Delete messages on server after successful read. Messages that cannot be read successfully will not be deleted.
false Do not delete messages on server (default).
markAsRead Boolean Specify whether successfully read messages will automatically be marked as read on the server. true

Mark messages as read on server after successful read. Messages that cannot be read successfully will not be marked read.
false Do not mark messages read on server (default).
withContent Boolean Specify whether the message body (HTML and/or plain text) should be populated. true Populate message body.
false Message body is empty (default).
withAttachments Boolean Specify whether attachments should be retrieved. true Retrieve attachments.
false Do not retrieve attachments (default).
withEmbeddedMails Boolean Specify whether attachments with mime type message/rfc822 should be retrieved as embedded messages. Requires withAttachments to be true to have an effect. true Retrieve attachments with mime type message/rfc822 as embedded messages.
false Do not retrieve attachments with mime type message/rfc822 as embedded messages, but as regular attachments (default).
withHeaders Boolean Specify whether messaging headers should be populated. true Populate messaging headers.
false Messaging headers are empty (default).
withRawContents Boolean Specify whether the raw message source should be retrieved. true

Retrieve raw message source.

This is similar to "view source" on most email clients, hence the output can be huge.
false Do not retrieve raw message source (default).
verifySignatures Boolean Specify whether for any signed messages a verification of the signature should be attempted. true

Verify signature.

To successfullly verify PGP signatures, a public key ring must be provided with the connection parameter.
false Do not verify signature (default).

Filter

Attribute Name Type Description Allowed Values
unreadOnly Boolean Specify whether only unread messages should be returned. true Return unread messages only.
false Return all messages (default).
fromTimestamp DateTime

Specify the beginning of a date range that should be used to retrieve messages (see also toTimestamp below).

Make sure that fromTimestamp and toTimestamp do not contradict each other as this is not checked.

 any DateTime
toTimestamp DateTime

Specify the end of a date range that should be used to retrieve messages (see also fromTimestamp below).

Make sure that fromTimestamp and toTimestamp do not contradict each other as this is not checked.

 any DateTime
subjectSubstring String

Specify a filter substring for the email subject. Only messages containing this string as a literal substring are returned.

subjectSubstring is case sensitive.

 any String with printable characters (case sensitive)
sender String

Specify a dedicated sender you want to retrieve messages from. Only message sent from this address are returned

 any valid email address (case insensitive)
senderRegex String Specify a regex filter to be applied to the mail sender. Only messages with the sender matching the filter expression are returned. any valid regular expression (Java style)
subjectRegex String

Specify a regex filter to be applied to the mail subject. Only messages with the subject matching the filter expression are returned.

 any valid regular expression (Java style)
attachmentNameRegex String

Specify a regex filter to be applied to the mail attachments. Only messages with at least one attachment's name matching the filter expression are returned.

Make sure that you are using withAttachments = true when reading the mails (see (25.2) JavaMail Library Reference#ReadFlags).

 any valid regular expression (Java style)

Step 2: Processing Messages

You can process emails as you need. Retrieved messages are delivered as an Array of ReceivedMail objects, which inherit from Mail and add some more attributes available after receiving:

jmail_process.png

Classes

ReceivedMail

Attribute Name Type Description Possible Values
sender String Contains the email address of the sender.
toRecipients Array of String Contains an array of TO recipient's email addresses.
ccRecipients Array of String Contains an array of CC recipient's email addresses.
bccRecipients Array of String Contains an array of BCC recipient's email addresses.
subject String Contains the email subject.
attachments Array of (25.2) JavaMail Library Reference#Attachment

Contains an array of email attachments.

If this is not populated, you may have set withAttachments = false when reading the mails (see (25.2) JavaMail Library Reference#ReadFlags).



plainTextContent String

Contains the plain text message if available.

Mime messages may contain HTML, Plain Text, or both.
htmlTextContent String

Contains the HTML message if available.

Mime messages may contain HTML, Plain Text, or both.
id String Contains the unique ID of the message within a folder on the mail server.
receiveDate DateTime Contains a timstamp indicating when the message arrived on the server.
sentDate DateTime Contains a timstamp indicating when the message has been sent.
headers Array of (25.2) JavaMail Library Reference#MailHeader

Contains an array of internet email headers.

If this is not populated, you may have set withHeaders = false when reading the mails (see (25.2) JavaMail Library Reference#ReadFlags).



embeddedMails Array of (25.2) JavaMail Library Reference#ReceivedMail

Contains an array of nested/embedded mail objects (attached email messages, e.g. .eml or .msg attachments).

If this is not populated, you may have set withAttachments = false when reading the mails (see (25.2) JavaMail Library Reference#ReadFlags).



receiveStatus (25.2) JavaMail Library Reference#MailReceiveStatus Contains detailed information about the receive status of the email.
folder String Contains the folder the message was read from. NULL <Inbox>.
folder path The folder path below <Inbox>.
signed Boolean Contains the signing status of the message. true Message is signed.
false Message is not signed.
encrypted Boolean

Contains the encryption status of the message.

detection is supported, however receiveStatus.success will always be false, as decryption is not yet supported

 true Message is encrypted.
false Message is not encrypted.
signatureVerificationResult (25.2) JavaMail Library Reference#SignatureVerificationResult Contains detailed information about the verification of signatures.


rawMessageText Blob

Contains the raw message.

If this is not populated, you may have set withRawContents = false when reading the mails (see (25.2) JavaMail Library Reference#ReadFlags).



Attachment

Attribute Name Type Description Possible Values
binary Boolean Indicates whether binaryContent or stringContent is used. true Attachment contents canl be found in, or shall be taken from, binaryContent.
false Attachment contents can/shall be found in, or shall be taken from, stringContent.
filename String The filename of the attachment.
  • can be NULL

Sending Messages

This is the name of the file as you want it to appear at the recipient's side, or vice versa.

Do not provide a local file name here and expect the library to load the attachment from that file. Use the File System Adapter instead, and provide the attachment as binary blob content (see binaryContent).
binaryContent Blob

Contains the binary content.

any Blob

Either one of binaryContent or stringContent is provided, depending on binary.
stringContent String

Contains the non-binary content.

any String

Either one of binaryContent or stringContent is provided, depending on binary.



mimeType String Contains the mime type (content type) of the attachment.

any valid MIME content-type, e.g. text/plain, image/png, application/octet-stream etc.

mimeType is unreliable upon receiving emails, i.e. can be NULL. Especially when reading from Exchange servers using exchange or office365 connections.
contentId String The content id of the attachment, a unique id across all attachments of the same message. When set to e.g. myUniqueId, you can refer to this attachment from HTML message content like <img src="cid:myUniqueId">
inline Boolean Controls whether the attachment is flagged with the corresponding content disposition tag. true Attachment is flagged, and will be displayed inline within a HTML message.
false Attachment is not flagged.

Step 3: Deleting/Moving Messages

After messages have been retrieved, they are often deleted or moved to a specific folder.

jmail_operations.png

Deleting Messages

Deleting messages is done by any one of the following operations:

  • deleteMessage

  • deleteMessages

  • deleteMessagesFiltered

deleteMessage and deleteMessages operate on an instance of ReceivedMail, means you can call them on objects returned by a read on the mailbox. deleteMessagesFiltered operates on a folder and a filter criterion. It deletes all matching messages.

Deletion is always "hard" deletion. Mail items are not moved to "Trash" or "Deleted Items". Once deleted, the message is gone.

deleteMessage

Parameter Types Direction Description
connection (25.2) JavaMail Library Reference#Connection in Specify the Connection object defining the mail server connection parameters to use (see Mail Server Connection).
mail

(25.2) JavaMail Library Reference#ReceivedMail

 in Provide a previously received mail object.

deleteMessages

Parameter Types Direction Description
connection (25.2) JavaMail Library Reference#Connection in Specify the Connection object defining the mail server connection parameters to use (see Mail Server Connection).
mail

Array of (25.2) JavaMail Library Reference#ReceivedMail

 in Provide an array previously received mail object.

deleteMessagesFiltered

Parameter Types Direction Description Allowed Values / Example
connection (25.2) JavaMail Library Reference#Connection in Specify the Connection object defining the mail server connection parameters to use (see Mail Server Connection).
folderPath

String

 in Specify a path to a folder to delete from. See note regarding folder handling.

orders/incoming
filter (25.2) JavaMail Library Reference#Filter in

Specify an instance of Filter containing the filter criteria.

If no filter criteria are set, i.e. if you provide an empty filter, all messages will be deleted.
affectedMessages Integer out Returns the number of deleted messages.

This might be lower than the total number of messages matching the filter if that number is huge, as mail servers may restrict the maximum number of messages processed in one call. If you want to be sure that all messages matching the filter are actually deleted, call this operation in a loop until affectedMessages becomes 0.

Moving Messages

Moving messages operates in instances of ReceivedMail, objects returned by a read on the mailbox. You can specify the target folder to move the message to.

Parameter Types Direction Description Allowed Values / Example
connection (25.2) JavaMail Library Reference#Connection in Specify the Connection object defining the mail server connection parameters to use (see Mail Server Connection).
mail (25.2) JavaMail Library Reference#ReceivedMail in Provide an array previously received mail object.
folderPath

String

 in

Specify a path to a specific sub-folder to move the message to. See note regarding folder handling.

POP3 connections will cause an exception to be thrown here, as POP3 does not support the concept of folders.

orders/incoming/accepted

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