Mail 11 (High Sierra): mail attachments "downloading" but never actually download

I have this issue also. I have tried all the suggestions above, but I cannot open some attachments they are stuck downloading. Not all attachments have this issue. Just from certain people sending them. PDF Documents Jpgs from particular clients are all stuck not downloading. If I ask my client to send the attachments to my gmail account, I can then go to Gmail through my browser to download the attachments. I have tried going to mail on iCloud.com through the browser, but they are not downloading from there either. All started happening after upgrading to high sierra and iOS11. I have an iPad still on iOS10, but the same emails with attachments are still stuck.

I am having this precise issue -- thanks for bringing it up. I check three accounts through Mail and, since upgrading to High Sierra, attachments to my work account go through fine, but ones in my Gmail and Yahoo accounts never download. The icon is there with a progress bar that says "downloading" but it never does.

I have the same problem as the others who have posted about this issue. If an email comes to the Apple Mail primary inbox, I can open the attachment. However, if goes to one of my rules designated local mailboxes, the file icon says "downloading" but the file cannot ever be opened. If I turn off the rule and the document is the originator re-sends the email and attachment and it stays in the primary inbox then I can open it. Hopefully, this bug can be corrected soon. I have a lot of rules set up and I receive a lot of attachments, so this is a major issue for me. It did not exist before I installed High Sierra. I have updated to 10.13.1, but the bug still exists.

When a pdf file comes in inbox it will show like this .

You have for a while and it depends upon these settings for the file to download .

You can click on apple logo > About this Mac > Manage > click on mail on the left side bar if you see this option dont automatically download attachments .

And if you click on it .

And if you click on optimize it will show like this .

I have found a fix by changing the "download attachments" check-box in Apple Mail Preferences from "Recent" to "All"

The logo that was "downloading" since yesterday now shows up in the same email, as follows:

You can also drag attachments out of the email message window, or choose File > Save Attachments.

Call Tech Support, Get to a Senior Level Support person.

According to my contact with Senior Tech, they don't read or pay attention to this forum.

He claimed Product Feedback - Apple is a place they do look. 😁

Apparently those of us using Rules and having Attachments is a unique, small part of Apple users.

Hence, this is not something effecting a large enough group for a prompt fix by Apple.

Please note this issue does affect NOT ONLY NEW mail.

I have years of mail with attachments in (sub)folders stored on iCloud. All the attachments can be viewed without problems through the iCloud webmail.

And I can also view/download any attachment in Mail app on another Mac running MacOS El Capitan.

It is the Mail app version bundled with High Sierra that never finishes downloading these older attachments. Even moving messages back to the inbox or sent box does not solve the problem.

I do not know if such problems already existed under MacOS Sierra. I was still using El Capitan until recently. I switched to High Sierra when I got a new MacBook some weeks ago.

Unlike others I have not experienced this issue with recent messages, even though I use mail rules to filter incoming mail and to sort sent messages.

My problem has to do with iCloud-account mail attachments of pre High Sierra days that are inaccessible (on a new MacBook) under the latest MacOS. And to stop using mail rules would not solve the issue in my case.

This is really annoying! Even though I can use iCloud webmail, or my older Mac running El Capitan, as a workaround to view the affected attachments.

I have already posted this as feedback at

https://www.apple.com/feedback/mail.html

and encourage others to do likewise, but wonder if Apple cares at all.

Thank you for sharing your experience.

Another bug of mail app, which was unintended resets of user's preference settings, took three months to be fixed by 10.13.2 update.

Mail Preference keeps changing since High Sierra Update

The bug of mail attachments seems not so common as the preference settings bug as only those who use rules actually encounter trouble, and so it may take more time to be fixed.

Anyone who has not yet submitted a bug report to Apple, please do so from the following link. It will be a start.

Feedback - Mail - Apple

Have been affected by this issue, as you can read in my previous posts in this thread. My problems had to do with viewing attachments in an iCloud mail account stretching back many years. And had less problems with recent message attachments.

Tried most of the suggested remedies to no avail. Now I decided to download a fresh copy of all my messages from iCloud. I roughly followed the (Yosemite) procedure outlined in:

https://discussions.apple.com/thread/7144486

I updated the instructions for High Sierra and made a few additional tweaks.

This procedure seems to have worked for me. Am sharing it, in case others will benefit from this approach as well. But try at your own risk. And back up all your data before proceeding!

1) Make certain all attachments get downloaded. Go to:

Mail settings -> icon Accounts -> tab Account Information -> select iCloud (or another IMAP account)

set if this is not already the case:

- Download attachments: all

2) close Apple Mail

3) go to this folder the user Library in Finder

~/Library/Mail/V5/MailData

( /Users/YourAccountName/Library/Mail/V5/MailData )

And move (= backup!) to the desktop the following,

any file beginning with:

- Envelope Index

any file beginning with:

- ExternalUpdates.storedata

- MessageUidsAlreadyDownloaded3

and if present a preference file:

- OpenedAttachmentsV2.plist

4) launch Apple Mail and confirm you want to import your messages. Then be patient as the import might take quite some time.

Hope this helps.

Sorry being late answering. I do get some but not all. I changed the preferences for mail download to None but it didn't help. Yesterday I got a mail with 2 pdf's that didn't download. Had to go to the mail server to being able to download them.

Today I used the app Onyx, for some maintenance. I found out there is a list over malware. If Mail suspects the attachment are "infected" the file can be downloaded by Mail. In the picture I sadly already have deleted the my downloads on the list. This is really cumbersome .

gillento -- I think you are right about the rules. I've been playing with this a lot and it is only attachments to messages that are filtered through rules; all others make it fine. I submitted a bug report and referenced this discussion, so fingers crossed for the next iteration.

Thanks again for bringing it up and for keeping us up to date.

I'm having the same issue, only since upgrading to High Sierra. I've tried the suggestions to work around but none have worked. With any of the methods I try to download the attachment (clicking the attachment icon, clicking the paperclip icon, going to File > Save Attachment), it either won't open the Save dialog at all, or if it does that step, nothing is saved to the Finder. The attachment icon changes from its original icon to a generic file icon with an unfilled progress bar and says "Downloading..." underneath.

One thing I noticed is that this is only happening with one client who is sending to me from a gmail account. My incoming address is not gmail, but rather an account set up with my hosting provider.

I use Rules to move email/ Invoices to a On My Mac folder. It is hit and miss with the attachments getting fully downloaded from various vendors. I have a funny feeling it is Off Hour emails that are effected. ie: Main computer shut down. Possibly iPad/iPhone email settings causing the hiccup. Those device settings to PUSH/FETCH can run constantly in the background. I'll turn those off and see what happens and verify Port settings in Incoming email ports.

How an email can come though from an email server and not have the attachment available is a mystery.

Seems like the email server deletes the attachment, hence you can't download it anymore.

Anyone know more about proper IMAP protocol. ie: What device can delete the attachment and not the email?