Email migration best practices Viktor Petersson | [email protected] | @vpetersson 

About us • Launched YippieMove in 2008 • Email migration experts • Worked with many well-known clients 

About YippieMove • The most powerful email migration tool • Support most email providers / servers on the market • Cost effective and scalable YippieMove offers (in addition to consulting) • Single-user migrations • Batch migrations • Self-service portals • API 

The basics 

Email Protocols Inbound • IMAP • POP3 • MAPI Outbound • SMTP Image from Apple.com 

DNS for email DNS • A-record • CNAME • MX-record • Priorities • Time To Live (TTL) • PTR, TXT, SPF... Image from sxc.hu 

DNS example google.com 74.125.224.36 [...] mail.google.com googlemail.l.google.com [...] google.com aspmx.l.google.com [...] A-record CNAME MX-record 

Big picture Recipient’s Server Recipient Sender MX-record SMTP CNAME A-record IMAP MAPI POP3 Sender’s Server SMTP DNS-lookup 

Best practices 

Objectives •Minimize impact on users • Before, during and after the migration • Ensure data integrity 

Pre-email migration checklist • Are you dealing with a single or multiple domains? • If large migration, can it be broken down into groups? • Do you have access to make DNS changes? • What is the TTL for the relevant DNS-records? • Do you have access to email administration? • Both source and destination 

Pre-email migration checklist • How are the clients accessing their email today? • Where are the messages stored (remote or locally)? • How can we access the messages? • What authentication methods are supported? • When is the lowest email transaction volume? • What about contacts and calendar? 

What are your options? • “Drag and drop”* • GAMME* • Google Apps sync for Outlook* • POP3-fetcher • Server-side scripting / tools (imapsync etc) • Email Migration-as-a-Service (such as YippieMove) • No migration * Limited by local bandwidth 

Email migration workflow The week before the migration • Drop the TTLs to the lowest value (usually 3600s/1h) • Prepare a list of all users, domains and aliases The week of the migration • Setup all accounts on the destination • Configure all domain and user aliases • Send out provisioned destination passwords to users 

Email migration workflow The day of the email migration (after business hours) • Change the DNS-records (MX and others) • Provision new source passwords • Assuming no other method is supported A few hours later (4xTTL is a good rule of thumb) • Begin the email migration 

Tips and tricks 

Tips and tricks for the email migration • Use OAuth for authentication when possible • Use application-specific password as fallback • TTLs can’t be trusted • Don’t provide users with the reseted password • They will change the password • It will lead to interruptions in the migration 

Tips and tricks for the email migration • Use “Live CDs” if you need to access customer data • MX-records does not affect access to the emails • mail.example.com => someserver.provider.com 

Tips and tricks for IMAP Open a connection • $ telnet mail.example.com 143 • $ openssl s_client -crlf -connect mail.example.com:993 Login • . LOGIN [email protected] password Logout • . LOGOUT 

Tips and tricks for DNS Verify MX records • $ dig example.com mx @8.8.8.8 Verify DNS records • $ dig example.com @8.8.8.8 • $ dig mail.example.com @8.8.8.8 Web-based alternatives: • MX-toolbox (mxtoolbox.com) • Your favorite domain registrar 

Tips and tricks for DNS 

www.YippieMove.com Viktor Petersson | [email protected] | @vpetersson The deck will be available at wireload.net/news 

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