Legacy Archive Data Management FAQs

Document created by user.oxriBaJeN4 Employee on Sep 7, 2015
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This article explores Frequently Asked Questions (FAQs) for Legacy Archive Data Management services.


Q: When should I import my data?

Mimecast recommends that you first complete your Connect, then begin your Legacy Archive Data Management process.


Q: I have been using Mimecast for some time.  Can I still import data?

Yes. You can choose to import historical data at any point.

Legacy Archive Data Management is limited to a one-time process.

Q: Is imported data de-duplicated for Single Instance Storage?

Yes. Import de-duplication is based on messageIDs and sent dates, and is stored in our Single Instance archive. It is important to verify that the solution used to export the data from your systems maintains the original messageIDs in the exported files. If providing mail for import from multiple systems where duplication will be present between systems, messageIDs should be verified to match between systems as well.

Deduplication is applied across imported items, and not against emails already in archive.

Q: What about Hybrid environments?

For Hosted Exchange or Office 365 deployments, you may not get access to export data.  The following options could then be considered:


  1. Deploy Exchange 2013 in hybrid mode, copy the mailboxes to Exchange 2013, and export to PST from there;
  2. Manually export each mailbox to a PST through Outlook;
  3. Use a third party provider.


More information is available from: http://help.outlook.com/en-us/140/hh310373.aspx.


Q: How long does Legacy Archive Data Management take?

From the time that the import data is provided to Mimecast, the time that it takes for your data to show in your Mimecast account is dependent on the following:


  • The amount of data provided
  • The current Legacy Archive Data Management jobs being processed by Mimecast
  • Any issues with the data, requiring further investigation or action, before the Ingestion can be completed


Your Mimecast Legacy Archive Data Management team will provide you with updates once your import is completed.


Q: How long does imported data get kept for?

Your Account Retention period will determine how long we keep any of your emails, including imported emails. This retention period is applied to the Sent Date of an email in the Archive, and once matched, the email is purged permanently from Mimecast.


For Example: Your Account Retention is set to 3653 days (10 years). You have imported data that is 5 years old - this data is therefore going to be retained in Mimecast for 5 years, until the Sent Date of the email is 3653 days old.

The scenario above excludes the possibility that the emails are removed manually by the Administrator.

Q: I have too much data to transfer using FTP. What do I do now?

Mimecast utilizes FTP transfers for all of our data migrations.  Our TLS encrypted FTP server resides in our data centre and provides a fast and secure transfer method for your data delivery.  All amounts are transferred utilizing this method. 


Q: What if my data link will be too slow for the FTP method?

Whilst your link may seem too slow for the amount of data you have, the FTP transfer rate is surprisingly fast.  Mimecast recommends you request an FTP account and run an upload test if you are unsure of the speeds you will achieve.


Q: I don’t want the FTP transfer to affect my normal daily usage. How do I avoid this?

In this instance, you could transfer the data out of hours. Filezilla has an option under the file transfer setting for default file exists action.  Setting the upload option to overwrite the file if the size differs or source file is newer will mean that if an unscheduled break occurs in the transfer, the client will skip any successfully uploaded files.  This will help ensure you transfer your data as efficiently as possible; many customers set this and then leave the upload going over the weekend.


Q: My FTP connection keeps resetting. What is going wrong?

Please check with your network team that the connection is not being reset by your Firewall.  Certain Firewalls will let a connection establish but then kill it if it reaches a specified data amount.  This will need to be disabled for your Mimecast historic data transfer.  Filezilla has an option under the file transfer setting for default file exists action.  Setting the upload option to overwrite file if size differs or source file is newer will mean that if an unscheduled break occurs in the transfer the client will skip any successfully uploaded files. 


Q: My FTP connection seems to fail. How do I resolve this issue?

The TLS encryption of the FTP server utilizes a specific port range of 49100 to 49200.Please make sure you apply an exception for the FTP server's IP address of for both inbound and outbound.  If you do not, the connection will be made initially and then fail.  Common error messages include:


  • "Error: GnuTLS error -53: Error in the push function"
  • "Error: Directory listing aborted by user"
  • “Error – failed to retrieve directory listing”


This is because your firewall permits the connection on the standard FTP port 21 but prevents the secondary port which is dictated by the Mimecast FTP server as part of its TLS encryption.


Q: What does the FTP error "Quota limit exceeded" mean?

Mimecast will set your FTP account size according to the amount of data you specify you have to upload.  If you exceed this amount the limit will need to be increased. Please contact the Legacy Archive Data Management team to extend your account quota.