Mega Mail Frustration!

Alameda

macrumors 6502a
Original poster
Jun 22, 2012
623
110
I was just driving home from work when my boss called me from Japan. He needed me to download and edit a file for him right away. So I stop in a Starbucks and login to our e-mail server. I do this using a VPN called Juniper Network Connect. Once I open the VPN, I start Apple's Mail client and it connects to our mail server.

I just spent twenty five minutes waiting for an 8 MB file. Ok, so Starbucks is slow. But the VPN software lists how many bytes it uploads and downloads. I had just left my office, so I only needed to download a single mail file. No other new mail had arrived. The 8 MB email arrived only after the Mail app downloaded a whopping 58.4 MB, and uploaded 5 MB! Why is the Mail app so inefficient, and does it always need to store six times more data than it actually needs? Does anybody know what's going on here?

As always, I thank you in advance for your help.
 

displaced

macrumors 65816
Jun 23, 2003
1,428
181
Gravesend, United Kingdom
I was just driving home from work when my boss called me from Japan. He needed me to download and edit a file for him right away. So I stop in a Starbucks and login to our e-mail server. I do this using a VPN called Juniper Network Connect. Once I open the VPN, I start Apple's Mail client and it connects to our mail server.

I just spent twenty five minutes waiting for an 8 MB file. Ok, so Starbucks is slow. But the VPN software lists how many bytes it uploads and downloads. I had just left my office, so I only needed to download a single mail file. No other new mail had arrived. The 8 MB email arrived only after the Mail app downloaded a whopping 58.4 MB, and uploaded 5 MB! Why is the Mail app so inefficient, and does it always need to store six times more data than it actually needs? Does anybody know what's going on here?

As always, I thank you in advance for your help.
There's a couple of things going on here. First of all, Mail may be doing other operations as well as downloading new mail. It might be clearing junk folders of old spam or downloading mailbox indexes to sync local message statuses with those on the server. You can view the Activity Window (from the 'Window' menu if I remember rightly) to see exactly what Mail's up to.

You're also seeing a symptom why email is an absolutely terrible transport mechanism for even modestly-sized files:

Email servers cannot natively handle anything other than text. The whole design of mail protocols assume you're sending and receiving messages made up of human-readable characters. Binary data (ZIP files, images, sounds, etc) CANNOT be understood by email servers. So how comes you can send and receive all these files? Well, all binary data is 'base64 encoded' into a plain-text representation of themselves. This process increases the size of every binary attachment by about a third.

However, email clients tend to show the size of the attachment as it would be in binary form, NOT the size of them in the larger base64 encoded form used when actually sending and receiving. So, your 8MB attachment actually caused 10.6MB to be downloaded.

Like I say, I can't directly account for the other 48MB that was downloaded, but Mail's Activity Window will tell you about that.

The crux of it is: Sending binary files via email is very inefficient. Might be worth exploring Dropbox or a similar service!

Cheers,
Chris
 

Alameda

macrumors 6502a
Original poster
Jun 22, 2012
623
110
Thank you very much for your help. It was useful and informative.

Still no luck. I logged in again, and it downloaded over 50 MB of data before I could begin reading e-mails. While I was waiting, I turned on my iPhone and downloaded the same e-mail and the attachment. While I was still waiting for OSX Mail to download the same file.

Something else seems to be wrong. Any more suggestions?

Thanks!!!
 
Last edited:

BrianBaughn

macrumors 604
Feb 13, 2011
6,803
1,107
Baltimore, Maryland
Does it download any data before you start Mail?

What kind of mail server is it? Do you really need to download all your mail and attachments on your laptop, or will just the headers do?
 

Alameda

macrumors 6502a
Original poster
Jun 22, 2012
623
110
Does it download any data before you start Mail?

What kind of mail server is it? Do you really need to download all your mail and attachments on your laptop, or will just the headers do?
Thank you for offering to help me.

The VPN client shows how many bytes transfer up and down. I usually connect with Mail not running. The client transfers around 25KB and it holds steady, then I launched Mail. The other day, I'd had Mail running on my LAN all day. I stopped at a Starbucks half an hour later, when my boss called. Only one message had arrived; the one he sent with the attachment. That's when I observed that Mail transfers vastly more data than it needs to. The same thing happened this morning. I will keep an eye on this

The mail server is MS Exchange. I access it by going to our corporate website, where I login with a password I generate with a device I keep on my keychain. This launches the Juniper VPN application I mentioned.
 

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