
Learn how to send audio files to clients with secure encrypted ZIPs, link delivery, and password best practices for reliable client workflows.
It's 6 p.m. on Friday, your voiceover client needs the final mastered WAV by morning, and the file is 180 MB. Email and most chat apps won't carry it reliably. The practical answer to how to send audio files to clients is to create an encrypted archive, upload it to a browser-based transfer service, and send the download link separately from the password.
Follow these four steps when a client needs a large audio deliverable quickly.
Choose a delivery channel. Use LinkShip, WeTransfer Pro, or a self-hosted SFTP server, then confirm the client can receive and open a download link. For a single MP3 or browser preview, an MP3-to-link workflow may be enough. For a master WAV, stems, and paperwork, use an archive.
Bundle the project files. Put the master, stems, cue sheet, and signed PDF contract in one clearly named folder. Create an AES-256 encrypted archive with 7-Zip on Windows, Keka on macOS, or this Linux command:
zip -e --encryption=AES256 archive.zip ./Project_Folder
Upload the archive. Use the selected transfer channel, then enable its available password protection, expiry, and download controls. The archive encryption remains important because it protects the file even if the link is forwarded or copied.
Separate the credentials. Send the link by email and the password by SMS or Signal. Don't put both credentials in the same message, especially when the recording is unreleased or commercially sensitive.

This approach takes a few extra minutes, but it avoids attachment failures and gives the client one controlled path to the deliverable. The sections below explain how to build, verify, and deliver the archive properly.
Email limits are the first obstacle. Gmail allows personal accounts attachments up to 25 MB, Outlook.com allows 20 MB, Yahoo Mail allows 25 MB, and iCloud Mail allows 20 MB, according to Google's attachment guidance. The limit applies to the complete encoded message, not only the visible file size, so headers and encoding overhead can push an apparently acceptable file over the threshold.
Audio grows quickly as duration and fidelity increase. A practical reference cited in this report on email attachment limits puts audio at roughly 1 MB per minute, meaning a 30-minute recording can approach 30 MB before higher-quality settings add further weight. A typical 10-minute WAV can be about 100 MB, while a 128 kbps MP3 can be close to 10 MB, as outlined in Fast.io's audio file-sharing guidance.
| Audio format | Size for a three-minute stereo file | Gmail 25 MB cap | Outlook 20 MB cap |
|---|---|---|---|
| WAV | Depends heavily on sample rate, bit depth, and duration | Often unsuitable for masters | Often unsuitable for masters |
| MP3 | Usually much smaller than WAV | Often viable for review | Often viable for review |
| FLAC | Smaller than uncompressed WAV while retaining audio data | Depends on the encoder and source | Depends on the encoder and source |
The format choice also changes what the client can judge. MP3 is convenient for rough approvals, but lossy compression isn't appropriate for a mastering sign-off. WAV or AIFF preserves the intended production quality, while FLAC reduces size without lossy encoding, though some clients may not have a familiar playback workflow.
Email can fail in less visible ways too. Oversized attachments may become cloud links automatically, be rejected by the recipient's server, or sit in quarantine instead of arriving promptly. Some services, including Gmail, replace files above the attachment cap with a Google Drive link. For a professional deliverable above the practical email threshold, use an encrypted archive and a browser link rather than forcing the attachment through.
The archive is the security boundary around the audio. It should contain the agreed deliverables, use a strong password, and open correctly before you send the link.
Install 7-Zip, then right-click the project folder and choose 7-Zip, followed by Add to archive. Select either the 7z or ZIP format. In the encryption area, enter the password twice and select AES-256 as the encryption method.
Use 7z when you control the receiving environment and want stronger container features. Choose ZIP when the client expects a familiar archive format and may be working on a computer without 7-Zip. Don't select ZipCrypto. It's a legacy option and isn't an acceptable choice for confidential masters.
Keka provides a straightforward macOS workflow. Drag the project folder into the app, select ZIP from the format menu, choose AES-256 in the encryption menu, enter the password, and create the archive.
The built-in Archive Utility is convenient for ordinary compression, but it doesn't provide the stronger encryption workflow needed here. A dedicated tool such as Keka avoids the common mistake of creating a password-protected archive with a weak legacy method.

For a 7z archive with encrypted headers, use:
7z a -t7z -mhe=on -p archive.7z ./Project_Folder
For a portable ZIP, use:
zip -e --encryption=AES256 archive.zip ./Project_Folder
The first command keeps filenames and archive headers private as well as the file contents. The ZIP command is more familiar to recipients, but you should still verify that the client's extraction tool supports the selected encryption method.
List the archive before delivery:
7z l archive.7z
or:
unzip -l archive.zip
Confirm that the archive lists the expected files and reports encryption. Finally, test it on a clean machine, ideally using a second operating system. A corrupt encrypted archive isn't just an inconvenience. It means a resent deliverable and a client who has lost confidence in the handoff.
The best tool depends on what you need to protect and what the client can open. 7-Zip is the strongest general default for studio work because it supports AES-256 and the 7z container, while also creating ZIP archives for broader compatibility. Its interface is less polished than some commercial alternatives, but it gives Windows users a dependable security path without adding a license cost.
Keka is a practical choice for Mac-based teams. It has a clean drag-and-drop workflow and supports AES-256 ZIP creation, which suits clients who expect a conventional .zip file rather than a .7z archive. The trade-off is that both sender and recipient need an extraction application capable of reading the selected encryption type.
WinRAR supports AES-256 in the RAR5 format and can be useful when a client specifically requests .rar. Its paid licensing model and less predictable cross-platform extraction experience make it a narrower choice for routine delivery.
| Tool | Default algorithm | AES-256 support | Cross-platform extraction | Cost |
|---|---|---|---|---|
| 7-Zip | Depends on selected container and settings | Yes | Strong with the right extractor | Free |
| Keka | Depends on selected archive format | Yes | Good when the recipient uses a compatible tool | Paid or donation-supported, depending on distribution |
| WinRAR | RAR5 AES-256 when configured | Yes | More variable outside supported environments | Paid license |
ZipCrypto should not be treated as “good enough.” Its known weaknesses mean that a strong password can't compensate for the algorithm itself. The practical decision rule is simple: use 7-Zip for most Windows and mixed Mac/Windows deliveries, Keka for Mac teams that need AES-256 ZIP files, and WinRAR only when the recipient explicitly requests RAR.
For additional document-sharing considerations, see this guide to encrypted document sharing. Whatever tool you choose, open the finished archive on a second operating system before sending it.
Once the archive is ready, the link becomes the delivery channel and email becomes only the place where you communicate with the client. Upload the .zip or .7z file to LinkShip, wait for the upload to finish, and configure the share settings before copying the URL.
Use the same password for the share and the archive only if that keeps the client workflow clear. The recipient then passes through the link protection and still needs the archive password after downloading. If you prefer separate credentials, use a different password for each layer and explain which one belongs to which screen.
Set the expiry to match the project turnaround. A short review window is appropriate for an unreleased voiceover or campaign master, while an active production may need longer access. If the client only needs one or two downloads, a view or download cap can reduce unnecessary redistribution.

Copy the share link and, where applicable, add the recipient email addresses used for delivery tracking. Send the URL through email, the client portal, or their preferred messaging channel, but keep the password out of that first message.
Browser playback is useful when the underlying audio format supports it, because clients can check a review file without immediately downloading another copy. For full-resolution WAVs, the encrypted archive remains the final handoff. Guidance from PiBox on secure audio sharing also supports streaming-first review and removing download access after decisions are complete.
Link-based delivery solves transport and workflow problems together. The archive protects the contents, while the share settings control who can reach the delivery and how long it remains available.
A reliable delivery starts at the bounce, not at the upload screen. Export the master or stems in the format agreed with the client, then check the sample rate, bit depth, loudness, and channel layout against the project specification. Open the file and listen to the beginning, middle, and end before you package anything.
Use a compact filename such as ProjectCode_v01_master.wav or ProjectCode_v02_revb.wav. Keep the working session separate from the client bounce. The archive should contain only what the recipient needs to review or approve.

Use this checklist:
A simple hash record can help confirm that the uploaded archive hasn't changed, especially when several people handle the handoff. For broader thinking about private media workflows, this review of Rooy Development provides useful context around controlled audio access.
Before marking the job complete, ask the client to confirm that the archive opens, the audio plays, and the received version matches the approved mix. That turns encrypted delivery into a repeatable studio habit instead of a Friday-night improvisation.
Sending the password separately isn't a weakness. It's a deliberate reduction in risk because an intercepted email no longer contains both the location and the key. Use an out-of-band SMS or voice call for a straightforward client relationship, or share the credential through a password manager vault such as 1Password or Bitwarden.
For sensitive sessions, a one-time secret link through a service such as Privnote can be appropriate. Another practical pattern is split delivery: send the share URL by email and the password through Signal or another separate chat. The important rule is that the two credentials shouldn't travel together by default.
Version control prevents a secure handoff from becoming confusing. Use names such as ProjectName_v01_master.wav and ProjectName_v02_master.wav, keep the working session in a separate archive, and don't overwrite a shared link while a client is still reviewing an earlier version. Create a new version when approval depends on a specific bounce. For a broader perspective on handling sensitive production information, you can browse privacy practices.
The client forgot the password. Confirm their identity through the established client channel, then send the password again through a separate channel. If the password may have been exposed, create a new archive with a new password.
The link expired. Check whether the project is still active, extend or replace the delivery according to your agreement, and avoid leaving unreleased material available indefinitely. The guidance on password-protected links covers the broader access-control logic.
The archive won't open on another operating system. Recreate it with a more widely supported format, verify AES-256 extraction on the client's platform, and test the replacement on a clean machine. Don't assume that every built-in archive utility supports the same encryption flags.
Is AES-256 excessive for an unreleased podcast? Usually, no. The extra step is modest, and unreleased audio, contracts, stems, and private interviews deserve protection. The right level depends on the sensitivity of the material and the client agreement, but ordinary email isn't a substitute for deliberate access control.
Can a large archive fail on an older drive? Yes. Legacy FAT32 systems may impose file-size restrictions, so ask the client about their destination system when they work with unusually large archives. A split archive or another delivery path may be necessary.
LinkShip gives studios a browser-based way to share audio, PDFs, images, and other client files through controlled URLs, with options such as password protection, expiry, view limits, replacement links, and analytics depending on the selected plan. Create an encrypted archive for your next master, publish it through LinkShip, and give the client a secure link plus a separately delivered password.
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