Retrieve Email Sequence Number from UID Message Fetch MailCore2

Question

Looking at Mailcore docs, I see a method to retrieve the sequence number of an email or emails by executing a fetch using the email UID. However, when looking at the Mailcore2 docs, I don't see any way to accomplish this. Is there a method for this in Mailcore2 that I am somehow not seeing, or a way to bubble up this information? I know it is possible in the command line, but I'd like to be able access it from inside my iOS app.

EDIT:

Here is why I am looking for this functionality:

We have a native iOS client that fetches the 10 newest emails at a time and saves them. Additionally, the client will fetch the next 10 older emails at a time and save them, as well as the lowest UID it has seen (minUID).

So we need to be able to continually fetch the next 10 older emails that exist on the server that the client has not yet stored or seen. (Therein lies the challenge).

Initially, we did this by fetching emails by UID in groups of 10, using our saved minUID minus 1 as the starting point for each fetch, and updating our minUID at the end of each fetch. However, as UIDs are not necessarily contiguous, the number of emails that was returned was inconsistent, and sometimes zero. To solve this problem, we thought it would be helpful to (before each fetch for the next 10 older emails), fetch the email with our stored minUID, check its current sequence number, and then fetch the next 10 older emails based on that sequence number.

shrishaster shrishaster · Accepted Answer · 2015-05-01T10:34:35

To fetch messages based on a sequence number, you can use the following function syncMessagesWithFolder:folderName:requestKind:uids:modSeq:

The below example will fetch you all the new/modified messages for the folder folder above sequence number highestModSeq.

MCOIMAPFetchMessagesOperation * op = [self.imapSession syncMessagesWithFolder:folderName
                                                                  requestKind:requestKind
                                                                         uids:[MCOIndexSet indexSetWithRange:MCORangeMake(1, UINT64_MAX)]
                                                                       modSeq:highestModSeq];

Retrieve Email Sequence Number from UID Message Fetch MailCore2

2 Answers