SMail - Secure Email

SMail - Secure Email

5,000 - 10,000 downloads

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SMail - Secure Email client for message encryption and authentication

User manual:

Security Features:
- S/MIME certificate public key or password based encryption and decryption
- S/MIME private key sign and signature verification
- S/MIME compress
- Supports S/MIME on POP3, IMAP4, SMTP and Microsoft Exchange ActiveSync
- Various format support: Clear text or opaque signing, binary encoding for internal attachment to reduce message size
PKI (Public Key Infrastructure) support:
- Certificate chain verification with revocation checking
- Resolve contact certificates on LDAP and Exchange server (No pre-installation of contact certificate is required for an enterprise PKI)
- Options on the certificate and CRL caching and refreshing
- Auto retrieval of CRL and intermediate CA based on information in the certificate
- Validate certificate revocation status using OCSP
- Validate signing certificate with Exchange server
- Well balanced between security and usability
- Supports smart card (PKCS#11 or java key store. Still looking for public smart card middle-ware solution)

Algorithms support:
RSA, 3DES, AES, SHA1, SHA256, SHA512

Free edition has advertisement.
You can try the full functions for 14 days after installation. (Some functions and Exchange support may be disabled after the free trial period).
You can purchase to remove advertisement and enable advanced features:
Advanced features: AES256, SHA256, SHA512, CRL, OCSP, LDAP
Exchange: Use Exchange account, AES256, SHA256, SHA512,

Email client features:
- IMAP push and Exchange ActiveSync push
- Exchange ActiveSync contacts and calendar synchronization, GAL
- Two pane view mode for tablet
- Compose message in HTML rich text
- Mailboxes list widget

What is encrypted:
Private keys, password, draft messages (derived device key or user's public key), some security settings
What is not:
Normal plain text messages. (Application password is for access verification and not used for full database encryption)

User Manual:
Please press the help button when creating an account.

Known issues:
- If you setup an Exchange account and set SMail as device administrator, later if you want to uninstall SMail, please go to Settings -> Security -> Device administrators and un-check SMail before uninstallation.
- S/MIME Compression is a component of S/MIME to reduce the message size and encryption processing time. It is only effective if the message has a very long text or is signed/encrypted and internal attachment encoding is "binary"
- Password based encryption, compression and binary encoding may not be well supported by other email clients which support S/MIME and may cause problems. Please test before real use
- PGP is not supported but in planning

Planned features:
More email operations, Search, Exchange Tasks and Notes

For the name Gimy, it should be pronounced like Jimmy, which means highly classified secret in Chinese.

Oops, the app crashed!!!
-> Post a complain -> Nothing changed -> We are all unhappy
-> Send developer an email to seek for help -> Problem is fixed -> We are all happy
This developer is willing to help. If you find any bugs or have any problem, feel free to send a message to .
Please describe your problem in details and provide as much information as you can.
Thank you!

Tags: smail, cliente de correo smail, smime, exchange smime, s/mime support, smail vs send inc, s/mime aes, 안드로이드 smail, mail client s/mime, s/mime exchange activesync.

Recently changed in this version

+ Added a dialog to display the recipients after the to or cc field is clicked
+ Setting timeout for CRL, OCSP and intermediate CA file retrieval
+ OCSP nonce checking options
Bug fixes
+ Mailboxes list widget (Android 4.x)
+ Allow to set mailboxes to display in the mailbox compact list (Please go to "Global settings -> Default mailboxes)
Various bug fixes
+ Pull to refresh
+ Change account color
Bug fixes and code restructuring

Comments and ratings for SMail - Secure Email
  • (62 stars)

    by Ashutosh Tiwari on 01/06/2014

    This the actual email client which I am looking for ..and best thing is HTML editing with bold,underline etc....1 star less due to font color options is not enable place fix it..

  • (62 stars)

    by Dave Brown on 22/05/2014

    This is the best android app I've found so far that supports inbound and outbound encryption on an Exchange account.

  • (62 stars)

    by Tim Backer on 11/04/2014

    Update: I've always liked all of the little things about the SMail GUI that makes it a workhorse and helps me be more productive. Had deal-breaker issues with it and our old Exchange 2003 server, but SMail is working great on our new 2010 server. Not using the secure functions, but it's a very good mail client overall. Less eye candy "iOS" styling, more about function.

  • (62 stars)

    by William Dennis on 08/04/2014

    After this last update it just doesn't work hardly at all. Stuff gets stuck in the drafts file now have inter errors at the server. What ever you did you broke it. Have to find one that works bye bye.

  • (62 stars)

    by TJ Mellis on 17/03/2014

    Hi Gimy.. Since last upgrade I have advertising with my paid pro version ??? Also keeps showing error messages "can not log in. Check settings passwords etc !! CAN YOU PLEASE FIX ASAP ??? MUCH APPRECIATED !! Excellent developer. Very fast to respond and assist when needed. This email client has EVERYTHING you could ask for or need if you want a great interface and utilize smime digital s

  • (62 stars)

    by Joseph Dearman on 23/02/2014

    u only add ur email to this thing

  • (62 stars)

    by Meadhbh Hamrick on 30/01/2014

    after trying several times to create the local key store and failing, i'm giving up. for a program that's supposed to do S/MIME, this is sort of a bad bug (and a deal killer.)