DOVECOT Overview. Timo Sirainen Chief Architect Co-Founder

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1 DOVECOT Overview Timo Sirainen, the Author of DOVECOT, started development in 2002 DOVECOT OY, the company behind Dovecot was established by Timo and his founder team with offices in Helsinki and Stuttgart. Markku Kenttä CEO Co-Founder Timo Sirainen Chief Architect Co-Founder Mikko Linnamäki Co-Founder The company provides commercial modules and professional services 24/7 and 8/5 enterprise support programs

2 References

3 Global market share for Dovecot (Open survey June ,33 million Dovecot server installations!

4 Debian Popularity Statistics: Courier Inst: Installed Old: Installed, but not used regularly Vote: Used regularly Recent: Upgraded recently

5 Debian Popularity Statistics: Cyrus Inst: Installed Old: Installed, but not used regularly Vote: Used regularly Recent: Upgraded recently

6 Debian Popularity Statistics: Dovecot Inst: Installed Old: Installed, but not used regularly Vote: Used regularly Recent: Upgraded recently

7 Why is Dovecot so popular? Since 2010, the largest ISPs of the world are following a trend to replace their previous, closed Black Box systems with open source software. The benefits of Dovecot backend are obvious: The control of the systems is back at the ISPs ISPs are not any more taken Hostage by the software vendors The economical effect of being able to rapidly adapt the systems to the market changes like Cloud Storage, is huge. Dovecot engine is one of the most scalable backends available today, already used by leading ISPs with tens of millions of users. The combination of Open-Xchange and Dovecot is the system of choice for ISPs that want to have the most modern UI with the best backend.

8 Dovecot Products and Services Dovecot Dovecot Mail Server clusters, Installed, migrated and managed. Commercial Products Dovecot Object Storage, Dovecot Archive Dovecot Cloud Storage Enterprise Support Premium and Basic support subscriptions, Professional Services

9 Architecture Load balancer -> proxy (director) -> backend Approx. 200k Sessions per proxy (2GB mem) CPU usage mainly SSL handling Approx. 12k Sessions per Backend (32GB mem) Primarily limited by available memory At least 2 proxies & 2 backends for redundancy Servers can be added & removed on the fly Crashed servers will be removed automatically Any component can fail, without users noticing it Backends are fully stateless -> linear scalability Proxies (directors) are organized as ring that communicates

10 DOVECOT Architecture (sample)

11 DOVECOT & OX Architecture

12 Object Storage Object storage advantages Massive linear scalability, scaling out transparently Geographic independence (highly available) Ability to use off-the-shelf hardware Cheaper than a dedicated SAN Object Storage disadvantages in general Scalability achieved by providing only simple APIs Adding a normal POSIX/NFS filesystem API slows down Latency is bad for non-local network storages Local network storage latency isn t great either NFS latency is also bad compared to local disks With 200 ms latency fetching 100 mails wastes 10 s just for waiting? The solution: DOVECOT Object Storage plugins à Local caching and prefetching technology minimizes latency waits Supports operation during network splits in multi-site cluster Later merge all changes no data loss! Possible to save only attachments to Cloud / Object Storage Support for Amazon S3, Scality, Dropbox, MS Azure, Rackspace Files (OpenStack), Ceph

13 Object Storage (high level) Local Object Storage Scality etc. Cloud Object Storage Amazon S3, Azure etc.

14 Elastic Cloud Storage Cluster

15 DOVECOT Archive DOVECOT Archive is a highly secure, cost efficient and scalable multi-domain archive solution for Telcos and ISPs. The product creates a new revenue stream by upgrading a groupware user to a customer which pays monthly fees for archiving and backups. s are archived to NFS or object storage in a format optimized for archiving (abox) For local object storages, use e.g. Scality or Ceph DOVECOT Archive has fast search capabilities in order to retrieve the wanted s in an efficient way. The system supports all known IMAP and SMTP servers.

16 Dovecot Archive High Level Architecture overview Mail Sender Incoming mail IMAP Incoming SMTP Server Copy of message Copy of message Archive SMTP/LMTP Encryption key Domain 1 Encryption key Domain 2 Encryption key Domain 3 Key Database Archive Writer (encrypt) Key lookup Mail User Outgoing mail IMAP Server Object Storage Cloud Mail Recipient Outgoing SMTP Server Groupware User Domain 1 SMTP Groupware Server Existing Mail Infrastructure IMAP IMAP (with optional archive extensions) Archive Reader (decrypt) Dovecot IMAP cluster Key lookup Domain 2 IMAP IMAP HTTPS Domain 3 Archive Web Interface Archive User

17 Dovecot Archive Key Features Easy setup with low costs, highly efficient & scalable solution Archive usually integrated with customer s SMTP server Initial data import via IMAP data encrypted with AES256 Especially important with cloud storage Identical attachments stored only once MULTI-DOMAIN architecture, multi-site clustering with object storage Customers SMTP server authentication via SSL client certificates and/or Username / Password Search: Fast full-text search of s and file attachments Search filter with time frame, keywords, recipients, sender, etc. Search multiple mailboxes, users folders and multiple folders

18 Migration from previous OpCo specific mail systems User-transparent migration from existing IMAP/POP3 systems No reconfiguring of IMAP clients No redownloading of messages Preserves message flags, IMAP UIDs, POP3 UIDLs, subscriptions, etc. Migration via IMAP/POP3 protocol Using dsync Master user/password login to old system Migration with zero downtime One user at a time migration Blocks of users later

19 Dovecot Summary Dovecot OY is offering support and professional services and licensed software to it s customers Most scalable and flexible backend with 53% market share Supports Object Storage on Amazon S3, Windows Azure, etc... Archive brings new revenue streams for Dovecot customers Dovecot, together with OX App Suite offers a complete and most advanced service package for large ISPs and Telcos More info:

20 Contact information Dovecot Main Office: Dovecot Oy Lars Sonckin Kaari Espoo Finland Tel Dovecot Germany: Hauptstrasse Stuttgart Tel Fax info_de@dovecot.fi