Mail drop not working all of the sudden (since 10.15.6?)

Hi, I know I am only repeating what others have said but if you go into iCloud in your browser you can use MailDrop from Mail there (even though it takes a while for the attachments to upload before you can hit the Send button).

Thx for response, but I do not access Mail from the iCloud web browser. I use Mail app on desktop using a 3rd party server account. As is the case with most people, this issue is new as I wasn't having this trouble before.

Same here. "Message cannot be sent by Mail Drop. try again later" (translated from German).

iMac with Catalina 10.15.6, local provider's mail account which always worked with mail drop.

Mail size is 30MB, free iCloud space is 30 GB.

I can observe that after each unsucessfull try which throws the above error message, I see "sending email 90MB" in the small status area left bottom. Every time I try and get the error message, the MB size increases by 30 MB, although I cancel the sending after error message appeared.

very strange, the mail deamon seems to upload data in the background for emails which have been canceled with an error message each.

I am excited to announce that having been an apple user for far too long sometimes I have this intuition that leads to the solution. In this case I came up with removing the signature from the email and presto it sent. I recently added a photo to my signatur, and I haven't tried sending with just the photo-free signature to see if it is just the photo causing the problem.

Well. That was it for me. I tried sending with a signature without the photo and it sent just fine. I added the photo to the signature again and did not send. So something about adding a photo to the signature caused the problem for me.

I had the same problem

Solution (for me):

In the Accounts (either from Mail or System Preferences)

click on iCloud (left sidebar)

click on iCloud Drive Options

check the Mail app so it can use the iCloud (mine was unchecked)

Copied the response from someone else, and YES, it resolved my issue.

««Well. That was it for me. I tried sending with a signature without the photo and it sent just fine. I added the photo to the signature again and did not send. So something about adding a photo to the signature caused the problem for me.»»

THANKS! (Will see if issue is resolved once I get on Big Sur soon)

I found it, at least for users of MobileMe. In addition to making sure that "Send large attachments with Maildrop" is checked in Preferences...Accounts, go to Mail>Accounts. Click on your MobileMe account. Make sure iCloud Drive is checked, and then click options. Click on the box next to Mail.app so that there is a check mark. That's it.

same problem in here.

I am using gmail with mc os catalina mail app. It says Unable to send attachments with Mail Drop. Try again later.

Before it was working perfectly.

The next time that happens to you go to Apple - Support - System Status and see what the Mail Drop status is.

Maildrop did that to me yesterday, for the first time.

It worked when I went into iCloud mail in Safari, although it took several minutes to upload the attachments before I could press Send.

Same issue here. After looking through multiple threads it appears that it's an OS bug. Seems like a big issue to not have fixed for a couple months now.