Techniques for automatically sorting emails into folders

• US 10,511,558 B2
• Filed: 09/18/2017
• Issued: 12/17/2019
• Est. Priority Date: 09/18/2017
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Bellegarda, Jerome R.
• Primary Examiner(s): Cox, Natisha D
• Application Number:
  US15/707,510
• Publication Number:
  US 20190089660A1
• Time in Patent Office: 820 Days
• Field of Search: None
• CPC Class Codes: G06F 16/353 into predefined classes
• CPC Class Codes: G06Q 10/107 Computer-aided management of electronic mailing [e-mailing]
• CPC Class Codes: H04L 51/212 using filtering or selective blocking
• CPC Class Codes: H04L 51/224 providing notification on incoming messages, e.g. pushed notifications of received messages
• CPC Class Codes: H04L 51/42 Mailbox-related aspects, e.g. synchronisation of mailboxes

Abstract

The embodiments set forth techniques for sorting emails within an email application. The technique can include: (1) accessing a plurality of emails, where each email is included in a respective folder of one or more folders, (2) establishing a set of n-grams based on the plurality of emails, (3) for each n-gram in the set of n-grams: calculating a respective normalized entropy for the n-gram, and calculating a respective indexing power for the n-gram based on its respective normalized entropy, (4) ranking the n-grams based on their respective indexing powers to establish a ranked list of n-grams, and (5) establishing, for each folder of the one or more folders, a respective set of high-value n-grams based on the ranked list of n-grams. In turn, the high-value n-grams can be compared against n-grams of a new email to identify a target folder into which the new email should be sorted.

Claims

1. A method for automatically sorting emails into one or more folders managed by an email application, the method comprising:

receiving a new email;

establishing a first set of n-grams based on the new email;

establishing, for the new email, a set of high-value n-grams based on an intersection of (i) the first set of n-grams based on the new email, and (ii) the respective sets of high-value n-grams for the one or more folders;

establishing, for each folder, a respective affinity score based on (i) the respective set of high-value n-grams for the folder, and (ii) the set of high-value n-grams for the new email;

identifying a target folder among the one or more folders having a strongest affinity score; and

in response to identifying that the strongest affinity score satisfies a second threshold value;

associating the new email with the target folder.

2. The method of claim 1, further comprising, prior to receiving the new email:

accessing a plurality of emails, wherein each email is included in a respective folder of the one or more folders;

establishing a second set of n-grams based on the plurality of emails;

for each n-gram in the second set of n-grams;

calculating a respective normalized entropy for the n-gram, and

calculating a respective indexing power for the n-gram based on its respective normalized entropy;

ranking the n-grams based on their respective indexing powers to establish a ranked list of n-grams; and

establishing, for each folder of the one or more folders, a respective set of high-value n-grams based on the ranked list of n-grams.

3. The method of claim 2, wherein the respective normalized entropy for each n-gram is based on (i) a count of the one or more folders, and (ii) a sum, for each folder of the one or more folders, of:

a first number of times the n-gram occurs in emails belonging to the folder relative to a second number of times the n-gram occurs within each email of the plurality of emails.

4. The method of claim 2, wherein the respective indexing power for each n-gram is based on subtracting the respective normalized entropy for the n-gram from a value of one.

5. The method of claim 2, further comprising, subsequent to establishing the ranked list of n-grams:

truncating the ranked list of n-grams in accordance with a first threshold value to cause at least one n-gram to be removed from the ranked list of n-grams.

6. The method of claim 5, further comprising:

storing the at least one n-gram in a set of low-value n-grams.

7. The method of claim 2, wherein each n-gram comprises one to N words derived from a subject, a body, or an attachment of at least one email of the plurality of emails.

8. The method of claim 1, further comprising, in response to identifying that the strongest affinity score does not satisfy the second threshold value:

establishing a third set of n-grams based on a relative complement of (1) (i) the respective sets of high-value n-grams for the one or more folders, and (ii) the set of low-value n-grams, with respect to (2) the second first set of n-grams based on the new email, wherein the third set of n-grams includes one or more n-grams; and

in response to identifying, among the one or more n-grams, that at least one n-gram of the one or more n-grams is observed within the new email a number of times that satisfies a third threshold value;

issuing a prompt to create a new folder into which the new email can be placed, wherein the new folder is based on the at least one n-gram.

9. The method of claim 8, further comprising:

in response to receiving an approval in association with the prompt;

creating the new folder, and

associating the new email with the new folder;

or

in response to receiving a refusal in association with the prompt;

retaining the new email in a default folder into which new emails are placed.

10. At least one non-transitory computer readable storage medium configured to store instructions that, when executed by at least one processor included in a computing device, cause the computing device to automatically sort emails into one or more folders managed by an email application, by carrying out steps that include:

receiving a new email;

establishing a first set of n-grams based on the new email;

establishing, for the new email, a set of high-value n-grams based on an intersection of (i) the first set of n-grams based on the new email, and (ii) the respective sets of high-value n-grams for the one or more folders;

establishing, for each folder, a respective affinity score based on (i) the respective set of high-value n-grams for the folder, and (ii) the set of high-value n-grams for the new email;

identifying a target folder among the one or more folders having a strongest affinity score; and

in response to identifying that the strongest affinity score satisfies a second threshold value;

associating the new email with the target folder.

11. The at least one non-transitory computer readable storage medium of claim 10, wherein the steps further include, prior to receiving the new email:

accessing a plurality of emails, wherein each email is included in a respective folder of the one or more folders;

establishing a second set of n-grams based on the plurality of emails;

for each n-gram in the second set of n-grams;

calculating a respective normalized entropy for the n-gram, and

calculating a respective indexing power for the n-gram based on its respective normalized entropy;

ranking the n-grams based on their respective indexing powers to establish a ranked list of n-grams; and

establishing, for each folder of the one or more folders, a respective set of high-value n-grams based on the ranked list of n-grams.

12. The at least one non-transitory computer readable storage medium of claim 11, wherein the respective normalized entropy for each n-gram is based on (i) a count of the one or more folders, and (ii) a sum, for each folder of the one or more folders, of:

a first number of times the n-gram occurs in emails belonging to the folder relative to a second number of times the n-gram occurs within each email of the plurality of emails.

13. The at least one non-transitory computer readable storage medium of claim 11, wherein the respective indexing power for each n-gram is based on subtracting the respective normalized entropy for the n-gram from a value one.

14. The at least one non-transitory computer readable storage medium of claim 11, wherein the steps further include, subsequent to

establishing the ranked list of n-grams:

truncating the ranked list of n grams in accordance with respect a first threshold value to cause at least one n-gram to be removed from the ranked list of n-grams.

15. The at least one non-transitory computer readable storage medium of claim 10, wherein the steps further include, in response to identifying that the strongest affinity score does not satisfy the second threshold value:

establishing a third set of n-grams based on a relative complement of (1) (i) the respective sets of high-value n-grams for the one or more folders, and (ii) the set of low-value n-grams, with respect to (2) the first set of n-grams based on the new email, wherein the third set of n-grams includes one or more n-grams; and

in response to identifying, among the one or more n-grams, that at least one n-gram of the one or more n-grams is observed within the new email a default number of times that satisfies a third threshold value;

issuing a prompt to create a new folder into which the new email can be placed, wherein the new folder is based on the at least one n-gram.

16. A computing device configured to automatically sort emails into one or more folders managed by an email application, the computing device comprising:

at least one processor;

and at least one memory storing instructions that, when executed by the at least one processor, cause the computing device to;

receive a new email;

establish a first set of n-grams based on the new email;

establish, for the new email, a set of high-value n-grams based on an intersection of (i) the first set of n-grams based on the new email, and (ii) the respective sets of high-value n-grams for the one or more folders;

establish, for each folder a respective affinity score based on (i) the respective set of high-value n-grams for the folder, and (ii) the set of high-value n-grams for the new email;

identify a target folder among the one or more folders having a strongest affinity score; and

in response to identifying that the strongest affinity score satisfies a second threshold value;

associate the new email with the target folder.

17. The computing device of claim 16, wherein the at least one processor further causes the computing device to, prior to receiving the new email:

accessing a plurality of emails, wherein each email is included in a respective folder of the one or more folders;

establishing a second set of n-grams based on the plurality of emails;

for each n-gram in the second set of n-grams;

calculating a respective normalized entropy for the n-gram, and

calculating a respective indexing power for the n-gram based on its respective normalized entropy;

ranking the n-grams based on their respective indexing powers to establish a ranked list of n-grams; and

establishing, for each folder of the one or more folders, a respective set of high-value n-grams based on the ranked list of n-grams.

18. The computing device of claim 17, wherein the respective normalized entropy for each n-gram is based on (i) a count of the one or more folders, and (ii) a sum, for each folder of the one or more folders, of:

a first number of times the n-gram occurs in emails belonging to the folder relative to a second number of times the n-gram occurs within each email of the plurality of emails.

19. The computing device of claim 17, wherein the respective indexing power for each n-gram is based on subtracting the respective normalized entropy for the n-gram from a value of one.

20. The computing device of claim 17, wherein the at least one processor further causes the computing device to, in response to identifying that the strongest affinity score does not satisfy the second threshold value:

establish a third set of n-grams based on a relative complement of (1) (i) the respective sets of high-value n-grams for the one or more folders, and (ii) the set of low-value n-grams, with respect to (2) the first set of n-grams based on the new email, wherein the third set of n-grams includes one or more n-grams; and

in response to identifying, among the one or more n-grams, that at least one n-gram of the one or more n-grams is observed within the new email a number of times that satisfies a third threshold value;

issue a prompt to create a new folder into which the new email can be placed, wherein the new folder is based on the at least one n-gram.