API IntegrationAPI Integration
SMTP message Transmission
High Level OverviewHigh Level Overview
Email In / Email Out
Zimbra and third party application shall be
integrated to the OneSync CRS platform using
SMTP over TLS.
The OneSync CRS platform shall return
converted voice messages as text to the third
party application using SMTP over TLS.
Figure 1 shows a high level representation of
the protocol flows between the third party
application and the OneSync platform
Logical Architecture and Protocol FlowLogical Architecture and Protocol Flow
1. Application shall send an email message containing an audio file
attachment to the CRS platform.
2. The audio file is processed by the CRS platform and converted into
3. The converted text is sent back by the CRP platform to the
application in an email message.
Security ConsiderationsSecurity Considerations
The connectivity for this service is over
the open internet and, with VPN
technology being impractical, email
messages shall be sent using SMTP over
TLS, to provide authentication and
INT-001 OneSync shall provide an
Account-Id to the third party application
after a successful registration. This
Account-Id shall be included by the third
party application in every conversion
request sent to OneSync.
INT-002 OneSync shall provide a digital
certificate to the third party application
after a successful registration. This
digital certificate shall be used by the
third party application during the TLS
TLS AuthenticationTLS Authentication
INT-003 The third party application shall
use SMTP over TLS for sending email
messages to OneSync.
INT-004 The OneSync mail server shall
request the client certificate from the third
party application during the TLS handshake.
INT-005 If the client certificate cannot be
validated, the OneSync mail server shall
terminate the SMTP connection.
INT-006 If the client certificate can be
successfully validated, the OneSync mail
server shall allow the SMTP data from the
third party application.
Conversion RequestConversion Request
High Level Overview
This section describes
the required format
of the conversion
the audio content to
be converted to text.
Inbound email message structureInbound email message structure
INT-007 The conversion request shall contain exactly one
(1) audio file attachment and exactly one (1) XML file
INT-008 If the conversion request contains more than one
(1) audio file attachment, the OneSync platform shall
reject the message and respond with an ‗Unconverted
Message‘, as specified in the Message Classification
INT-009 If the conversion request contains no audio file
attachments, the OneSync platform shall reject the
message and respond with an ‗Unconverted Message‘, as
specified in the Message Classification section.
INT-010 If the audio file contains no spoken word, for
example music or an unsupported language, the OneSync
platform shall reject the message and respond with an
‗Unconverted Message‘, as specified in the outbound
message from OneSync.
Standard Email HeadersStandard Email Headers
The header of the conversion request shall contain standard SMTP
headers, in the following format:
INT- 011 The From header shall be an RFC2822 compliant email
address and shall be specified by the third party application.
INT- 012 The To header shall be set to one of the following email
INT- 013 The Date header shall contain the date and time the
message was created in the third party application and formatted
as per RFC2822. e.g. Thu, 2 Apr 2009 00:00:00 +0100
INT- 014 The Subject header shall be specified by the third party
application and returned by OneSync in the outbound email
message. N/A No
INT- 015 The Message-Id header shall contain a unique identifier
for the message and shall be returned in the outbound email
message. 80 characters maximum Yes INT-016 If any other
standard headers are received in the conversion request that are
not specified above, these additional headers shall be ignored by
the OneSync platform and normal message processing shall
Custom X-headersCustom X-headers
INT- 017 The X-Version header shall contain the version
number of the API being used. This header shall be set to
INT- 018 The X-Message-Class header shall contain an
indication of the type of message received. Permissible
values for this header are:
◦ Voicemail – to indicate a voicemail message
◦ Spoken-SMS – to indicate a spoken SMS message
◦ Blog – to indicate a blog posting
◦ Memo – to indicate a spoke memo message
◦ Test-Message – to indicate a test message
◦ Unknown – if the voice message is none of the above categories If
any other value is received in this header, the conversion request
shall be rejected. If this header is not included, the OneSync
platform shall assume a default value of ‘Unknown’
INT-019 X-headers may be specified in the conversion
request — the X-headers shall be ignored by the OneSync
platform and normal message processing shall continue.