Cloud fax services and fax to email

See also

Sources

1. 1
   In DA 19-1247 (December 2019) the FCC Consumer and Governmental Affairs Bureau ruled that an online fax service that receives faxes and delivers them as electronic files is not a telephone facsimile machine under the TCPA.

   Amerifactors Financial Group LLC Petition for Expedited Declaratory Ruling (DA 19-1247) · Declaratory Ruling, discussion section (paragraph not verified; PDF text did not extract) · Checked 2026-10-14
2. 2
   Consensus states that eFax Corporate supports HIPAA Business Associate Agreements with healthcare providers.

   eFax compliance features · HIPAA section · Checked 2026-10-14
3. 3
   Consensus states that eFax Corporate has obtained HITRUST CSF certification.

   eFax compliance features · HIPAA section, HITRUST statement · Checked 2026-10-14
4. 4
   When a cloud fax service delivers inbound faxes containing PHI as email attachments, the email delivery leg is itself a transmission of ePHI that the covered entity must assess under the HIPAA transmission security standard, not only the fax leg.inferred

   45 CFR § 164.312 - Technical safeguards · 45 CFR 164.312(e)(1) · Checked 2026-10-14
5. 5
   FCC rule 47 CFR 64.1200(a)(4) prohibits using a telephone facsimile machine, computer or other device to send an unsolicited advertisement to a telephone facsimile machine unless the listed conditions are met.

   47 CFR § 64.1200 - Delivery restrictions · 47 CFR 64.1200(a)(4) · Checked 2026-10-14
6. 6
   A sender of fax advertisements must honor an opt-out request within the shortest reasonable time from the request, not to exceed 30 days.

   47 CFR § 64.1200 - Delivery restrictions · 47 CFR 64.1200(a)(4)(v) · Checked 2026-10-14
7. 7
   An unsolicited fax advertisement sent under the 64.1200(a)(4) exceptions must carry an opt-out notice that is clear and conspicuous and on the first page of the advertisement.

   47 CFR § 64.1200 - Delivery restrictions · 47 CFR 64.1200(a)(4)(iii)(A) · Checked 2026-10-14
8. 8
   The HIPAA Security Rule requires mechanisms that record and examine activity in information systems that contain or use electronic protected health information.

   45 CFR § 164.312 - Technical safeguards · 45 CFR 164.312(b) · Checked 2026-10-14
9. 9
   Encryption of electronic protected health information in transmission is an addressable implementation specification under the HIPAA Security Rule, to be implemented whenever deemed appropriate.

   45 CFR § 164.312 - Technical safeguards · 45 CFR 164.312(e)(2)(ii) · Checked 2026-10-14
10. 10
    The HIPAA Security Rule requires covered entities and business associates to implement technical security measures to guard against unauthorized access to electronic protected health information being transmitted over an electronic communications network.

    45 CFR § 164.312 - Technical safeguards · 45 CFR 164.312(e)(1) · Checked 2026-10-14
11. 11
    RingCentral email-to-fax is addressed to the recipient's 10-digit fax number followed by @rcfax.com.

    How to send a fax online · Send a fax by email steps · Checked 2026-10-14
12. 12
    RingCentral delivers received faxes as email attachments and also keeps them in the online account alongside voicemails.

    How to send a fax online · Receiving faxes paragraph · Checked 2026-10-14
13. 13
    In RingCentral email-to-fax, text in the email subject line triggers an automatic cover page, and a custom cover page can be attached separately.

    How to send a fax online · Send a fax by email steps · Checked 2026-10-14
14. 14
    RingCentral email-to-fax requires the sender's email to be connected to RingCentral as a trusted email account.

    How to send a fax online · Send a fax by email prerequisite sentence · Checked 2026-10-14
15. 15
    RFC 3965 defines simple-mode Internet fax as a profile of standard Internet mail, using SMTP and MIME and ordinary mail addressing rather than a separate fax transport.

    RFC 3965: A Simple Mode of Facsimile Using Internet Mail · RFC 3965 sections 1, 2.1.1, 2.1.3 and 2.2 · Checked 2026-10-14
16. 16
    RFC 3965, published December 2004, obsoletes RFC 2305 and states that it makes no technical changes to it.

    RFC 3965: A Simple Mode of Facsimile Using Internet Mail · RFC 3965 header and Abstract · Checked 2026-10-14
17. 17
    Under RFC 3965 a relay failure of an Internet fax message produces a failure message, preferably a Delivery Status Notification.

    RFC 3965: A Simple Mode of Facsimile Using Internet Mail · RFC 3965 section 2.3.1 · Checked 2026-10-14
18. 18
    RFC 3965 requires sending Internet fax devices to be able to write, and receiving devices to read, minimum-set TIFF files under the TIFF for Facsimile profile S.

    RFC 3965: A Simple Mode of Facsimile Using Internet Mail · RFC 3965 section 4 · Checked 2026-10-14
19. 19
    RFC 4142 Full-mode Fax Profile for Internet Mail requires conforming implementations to also conform to RFC 3965 and RFC 2532, adding negotiation features comparable to classic T.30 fax.

    RFC 4142: Full-mode Fax Profile for Internet Mail (FFPIM) · RFC 4142 section 1 · Checked 2026-10-14
20. 20
    RFC 4142 requires support for UA-based post-hoc capability negotiation per RFC 3297, while ESMTP-based CONNEG negotiation per RFC 4141 is optional.

    RFC 4142: Full-mode Fax Profile for Internet Mail (FFPIM) · RFC 4142 sections 2.1 and 2.2 · Checked 2026-10-14
21. 21
    In Sinch Fax to Email one fax number can route to multiple email addresses and many numbers can route to one email address, configurable in the dashboard or through the emails API endpoints.

    Fax to Email · How emails are associated with numbers; email endpoints list · Checked 2026-10-14
22. 22
    Sinch states that its secure Fax API URL https://fax.api.sinch.com enforces TLS 1.2.

    HIPAA compliance (Fax) · What we already do for you · Checked 2026-10-14
23. 23
    The Sinch Fax API supports both fax-to-email, forwarding a fax received on a Sinch number to configured email addresses, and email-to-fax, delivering an email as a fax.

    Fax to Email · Overview and How It Works · Checked 2026-10-14
24. 24
    Sinch states that supported fax-to-email file types are Word, PDF and TIF.

    Fax to Email · Fax to Email page, supported file types sentence · Checked 2026-10-14
25. 25
    The Sinch Fax API global endpoint https://fax.api.sinch.com/ automatically routes each request to the appropriate regional server.

    Fax API reference overview · Global URL · Checked 2026-10-14
26. 26
    Sinch's HIPAA steps for the Fax API are to uncheck both boxes in the service's HIPAA section so documents are not stored, enable two-factor authentication and use HTTPS for all webhook URLs.

    HIPAA compliance (Fax) · What you need to do · Checked 2026-10-14
27. 27
    Sinch offers a free-to-sign HIPAA Business Associate Agreement for the Fax API through the HIPAA section of its Build dashboard, signed via DocuSign.

    HIPAA compliance (Fax) · What you need to do · Checked 2026-10-14
28. 28
    When storage is enabled, Sinch keeps Fax API logs and media for 13 months, accessible through the API, and deletes them afterwards.

    Fax API reference overview · Deletion and data retention · Checked 2026-10-14
29. 29
    The TCPA defines a telephone facsimile machine as equipment that can transcribe text or images from paper into an electronic signal and transmit it over a regular telephone line, or transcribe text or images from such a received signal onto paper.

    47 U.S. Code § 227 - Restrictions on use of telephone equipment · 47 U.S.C. 227(a)(3) · Checked 2026-10-14
30. 30
    The TCPA requires a person sending a fax from a computer or other electronic device to mark the transmitted pages in a top or bottom margin with the date and time sent, an identification of the sender and the telephone number of the sending machine or sender.

    47 U.S. Code § 227 - Restrictions on use of telephone equipment · 47 U.S.C. 227(d)(1)(B) · Checked 2026-10-14
31. 31
    The TCPA makes it unlawful to use any telephone facsimile machine, computer or other device to send an unsolicited advertisement to a telephone facsimile machine, subject to statutory exceptions that include an established business relationship and a compliant opt-out notice.

    47 U.S. Code § 227 - Restrictions on use of telephone equipment · 47 U.S.C. 227(b)(1)(C) · Checked 2026-10-14
32. 32
    Microsoft Teams Direct Routing treats fax machines as analog devices, which must connect through an Analog Telephony Adapter supported by the certified SBC vendor.

    Direct Routing - Connecting analog devices · Introduction and Considerations · Checked 2026-10-14
33. 33
    Microsoft's Direct Routing analog-device guidance offers fax only as an ATA-and-SBC attachment, which suggests Teams Phone migrations needing fax-to-email must add a third-party fax service or fax server.inferred

    Direct Routing - Connecting analog devices · Considerations · Checked 2026-10-14
34. 34
    In Telnyx, a Programmable Fax Application handles inbound fax traffic and authentication, while an Outbound Voice Profile governs outbound traffic, billing and allowed destinations.

    Programmable Fax - Get started · Core Concepts · Checked 2026-10-14
35. 35
    Telnyx Programmable Fax accepts PDF, TIFF, JPEG, PNG, DOC, DOCX, RTF and TXT documents for outbound faxes.

    Send a fax (API reference) · Send a fax reference, supported file types note · Checked 2026-10-14
36. 36
    Telnyx Programmable Fax limits an outbound fax to 50 MB and 350 pages, returning file_size_limit_exceeded or page_count_limit_exceeded when exceeded, and caps a multipart contents upload at 20 MB.

    Send a fax (API reference) · Body parameter contents and error descriptions on the Send a fax reference · Checked 2026-10-14
37. 37
    Telnyx converts a received fax to a PDF and signals with the fax.received webhook that the file is ready to download from media_url.

    Receive a fax via API · Example Webhooks: PDF has been generated and is ready for download · Checked 2026-10-14
38. 38
    The Telnyx receive-a-fax guide states the inbound media_url is valid for 10 minutes, but its own example URL carries X-Amz-Expires=7200 (two hours), so the actual expiry is unresolved.disputed

    Receive a fax via API · Example Webhooks: PDF has been generated and is ready for download (prose and sample payload) · Checked 2026-10-14
39. 39
    For an inbound Telnyx fax the documented webhooks are fax.receiving.started, then fax.media.processing.started, then fax.received when the PDF is ready, with fax.failed and a failure_reason sent on failure.

    Receive a fax via API · Example Webhooks · Checked 2026-10-14
40. 40
    The Telnyx send-a-fax quality parameter accepts normal, high, very_high, ultra_light or ultra_dark and defaults to high.

    Send a fax (API reference) · Body parameter quality · Checked 2026-10-14
41. 41
    Telnyx Programmable Fax sends a fax with a POST to /v2/faxes carrying a connection_id, a media_url and E.164 to and from numbers, and an HTTP 202 response means the fax was initiated.

    Programmable Fax - Get started · Hello World Example · Checked 2026-10-14
42. 42
    When store_media or store_preview is true, Telnyx stores the outbound fax media or preview at a temporary URL that expires 10 minutes after creation.

    Send a fax (API reference) · Body parameters store_media and store_preview; response field descriptions · Checked 2026-10-14
43. 43
    The Telnyx send-a-fax request has a boolean t38_enabled parameter whose default is true.

    Send a fax (API reference) · Body parameter t38_enabled · Checked 2026-10-14
44. 44
    The Telnyx reference describes t38_enabled as the flag to disable the T.38 protocol, wording that conflicts with its name and true default, so the parameter's polarity should be tested rather than taken from the description.inferred

    Send a fax (API reference) · Body parameter t38_enabled, description field · Checked 2026-10-14
45. 45
    Twilio ended support for Programmable Fax on December 17, 2021, after a one-year end-of-life notice published December 17, 2020.

    Programmable Fax end of life one year notice · Changelog entry dated Dec. 17, 2020 · Checked 2026-10-14
46. 46
    Integration guides or code that call Twilio Programmable Fax describe a service retired in December 2021 and should not be used as current instructions.inferred

    Programmable Fax end of life one year notice · Changelog entry dated Dec. 17, 2020 · Checked 2026-10-14
47. 47
    Twilio's Programmable Fax end-of-life notice named mFax by Documo as a migration partner.

    Programmable Fax end of life one year notice · Changelog entry dated Dec. 17, 2020 · Checked 2026-10-14
48. 48
    For persistent ATA fax failures on Webex Calling, Cisco suggests lowering the fax machine baud rate to 9600 or 2400 bps, changing its ECM setting and sending fewer pages per call.

    Improve fax transmission with your ATA · What to do next · Checked 2026-10-14
49. 49
    On Webex Calling ATAs, faxes are sent with T.38 mode disabled by default, and an administrator can switch the ATA to T.38 to improve transmission.

    Improve fax transmission with your ATA · Before you begin · Checked 2026-10-14
50. 50
    Cisco states that when T.38 is enabled on a Webex Calling ATA, faxes are not encrypted.

    Improve fax transmission with your ATA · Before you begin · Checked 2026-10-14
51. 51
    Zoom Phone online fax can send one fax to up to 50 recipients at once.

    Online fax | Zoom Phone · Feature list and FAQ · Checked 2026-10-14
52. 52
    Zoom Phone online fax must be enabled by an account admin, who can enable it for specific users only.

    Online fax (Zoom blog) · Paragraph containing 'once it's enabled by an account admin' · Checked 2026-10-14
53. 53
    Zoom's product page states that plans include 50 inbound or outbound fax pages per user pooled at the account level, with unlimited fax on Zoom Workplace Business Plus and higher.

    Online fax | Zoom Phone · Pricing and FAQ section · Checked 2026-10-14
54. 54
    Zoom Phone online faxes can be routed to individual users, auto receptionists, call queues and shared line groups.

    Online fax | Zoom Phone · Feature list · Checked 2026-10-14
55. 55
    As published in March 2025, Zoom Phone online fax handles files up to 50 MB and 300 pages per fax.

    Online fax (Zoom blog) · Paragraph containing 'send files up to 50MB and 300 pages' · Checked 2026-10-14
56. 56
    Zoom states that Zoom Phone online faxes are encrypted in transit with TLS and stored securely.

    Online fax | Zoom Phone · Security section · Checked 2026-10-14

Documents

Cite this page

WarmTransfer. (2026, October 14). Cloud fax services and fax to email. WarmTransfer. https://warmtransfer.net/knowledge/cloud-fax-services

@misc{warmtransfer-cloud-fax-services,
  title  = {Cloud fax services and fax to email},
  author = {{WarmTransfer}},
  year   = {2026},
  url    = {https://warmtransfer.net/knowledge/cloud-fax-services},
  note   = {Verified 2026-10-14}
}