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E-mail Usability

KYNGIN mail services are tuned for performance and usability by all standards compliant (IMAP+SMTP) mail clients.  Unless a filesystem quota is applied manually by a facility manager, your first usability issues will become apparent from your mail user agent (Outlook, Thunderbird, iPhone/Android Mail, etc). 

For Microsoft Outlook you'll notice errors around 50GB of total storage utilized per mail account.  These are Outlook limits for mailbox sizes.  We have a fix for this below (scroll down).

For most other clients such as Mozilla Thunderbird, or Apple Mail, iPhone/Android Mail, mail quantity limits will be entirely based upon hardware and compute limits of your local device, and problems are typically much more rare.

Sending Limits

KYNGIN/MX sending limits are set at 100MB per mail message. Email is encoded during send, and binary data will grow 20-30% in size.

After encoding, you should safely be able to send around 70MB of data per e-mail. If you have trouble with size limits, it's almost always the recipient party servers limiting your deliverability. A bounce message will usually explain this. The largest e-mail providers typically have around 25-35MB limits, and because of encoding, we recommend still keeping e-mails below 15MB.

Sending to people in the same domain, or 2 domains hosted on KYNGIN, will not have any trouble sending upward of 60-70MB. To be safe from any potential inconvenience, we recommend 50MB e-mail sizes at maximum.

Further Details

With KYNGIN mail services, the predominate way users login and check their email is via a standalone email client (or Mail User Agent, abbreviated as MUA).  This is usually in the form of Microsoft Outlook, Mozilla Thunderbird, Apple Mail (included on every Apple Device), Android Mail (included on every android device), or webmail services in which you access your e-mail through a web browser.

MUA's use two different open Internet standard protocols to communicate with the KYNGIN servers hosted here at Mindpack Studios.  The first protocol, IMAP provides a communication mechanism for your mail client to manage e-mail that is hosted on the mail server.  Think of IMAP as the communication channel that allows your MUA to organized and store e-mails on the server.  Marking e-mails as 'read', or 'replied-to', or moving e-mails between folders, or flagging e-mails as junk causes the email client uses a public Internet Standard protocol called IMAP to communicate with the mail server.  These protocols allow the MUA to quickly be informed of folder updates, incoming e-mail, or even synchronizations from other devices.

Fixing Outlook

(Fix for latest version of outlook)

If you do have more than 50GB of e-mail in your outlook client. Our current recommendation is to move older e-mail into an archival folder, and then set that folder as no longer subscribed by right clicking the folder, selecting 'IMAP Folders', and then un-subscribing from said folder. Unsubscribed folders should still be visible, but will not keep e-mail on the local device.

(Fix for older version of outlook)

For older version of Outlook, a registry hack does work which eliminates this problem. Open the registry editor (regedit.exe) and locate these keys:

  • Outlook 2003


  • Outlook 2007


  • Outlook 2010


  • Outlook 2013


  • Outlook 2016 and above


Then add the following 2 DWORDS (If they already exist, please update them):

MaxLargeFileSize with a decimal value of 200000
WarnLargeFileSize with a decimal value of 190000

This will set the maximum OST/PST file size of 200GB, and a warning size of 190GB. You can feel free to increase those values higher, though we'd recommend keeping them below 4TB or you're likely to see problems.