> ## Documentation Index
> Fetch the complete documentation index at: https://docs.heymilo.ai/llms.txt
> Use this file to discover all available pages before exploring further.
> Contact blasts let you send email, SMS, or automated phone calls to selected candidates on an interviewer—for nudges, urgent fills, and re-engagement—without messaging people who don’t need it.
# Contact Blasts
### How to start a blast
1. Open the **Interviewer** (job posting).
2. Go to **Candidates**.
3. **Select** who should receive the blast: **one** candidate, **any subset**, or **select all** (per your UI).
4. Click **Actions**.
5. Choose **Blast**.
6. In the blast flow: pick **channel** (email / SMS / phone), add **message** where required, apply **filters** if offered, review **eligible** vs **skipped**, then **enqueue** / send.
### How it works (overview)
* **Audience**: Driven by **who you selected** on the candidate list, plus any **filters** in the blast UI (e.g. skip completed or knocked-out candidates when those options exist).
* **Channel**: **Email**, **SMS**, or **Phone call**.
* **Message**: You write copy for **email** and **SMS** only; **phone** blasts are **automated** (no script from you).
* **Review**: The product shows counts: **eligible** vs **skipped** and a **preview** before you send.
### Email blasts
* **Subject**: Up to **200** characters (per product limits).
* **Body**: Up to **2000** characters.
* **Requires** valid **email** addresses.
* Strong for **detail**, **links**, and a more **formal** tone.
### SMS blasts
* **Message**: Up to **2000** characters (per product limits).
* Variables such as **`{{candidate_name}}`** where the product supports them.
* **Requires** candidate **phone numbers** and SMS setup (see Phone Numbers).
* Strong for **short**, urgent, mobile-first nudges.
### Phone call blasts
Automated outbound **calls**—you **do not** write call content in the blast flow.
* **Recipients**: Typically candidates with a number tied to **prior SMS engagement** (per workspace rules).
* **Filtering**: Can align with other channels (e.g. avoid completed / knocked out when those filters are on).
* **System**: Calls are **initiated automatically**; bad numbers are **skipped**.
* **Timing**: Often constrained to **business hours.**
* **Rate limit**: **One call per candidate per 6 hours**; skips may show **`rate_limited`**.
### Rate limiting
| Channel | Limit (typical) |
| --------- | ----------------------------------- |
| **Email** | **1** per **hour** per candidate |
| **SMS** | **1** per **hour** per candidate |
| **Phone** | **1** per **6 hours** per candidate |
Candidates contacted too recently are **skipped** automatically; results may show **`rate_limited`**. That protects deliverability and candidate experience.
### Smart filtering (why “eligible” \< “selected”)
Depending on options you choose, the product may skip people who:
* **Already completed** the interview
* Are **knocked out** / disqualified
* **Don’t have** the right contact method (email / SMS / eligible phone path)
* Hit **rate limits**
* **Phone:** don’t meet **SMS history** (or similar) requirements
Always read the **eligible** vs **skipped** summary before you enqueue.
### Blast history and metrics
1. From the **Interviewer**, go to **Candidates**.
2. Under **Contact History**, you'll see the message sent to your selected candidates
### Recruiter best practices
* **Corporate / desk roles**: Email for clarity; send in **business hours** when possible.
* **High-volume / hourly**: SMS for speed; keep copy short; one clear CTA + deadline.
* **Phone**: Use when prerequisites are met and you want a **high-touch** signal.
* **Copy**: Lead with **value** (role, pay band, deadline) not guilt.
* **Cadence**: Respect **rate limits**; avoid hammering the same list daily.
* **Pilot**: Test on a **small selection** before blasting everyone.
### Troubleshooting
| Issue | What to check |
| -------------------- | ------------------------------------------------------------------------------------------- |
| **Can’t find Blast** | You must be on **Candidates** with at least one row **selected**; then **Actions → Blast**. |
| **Low eligible** | Completed / knocked out; missing email or phone; rate limits. |
| **Phone won’t run** | SMS engagement requirement; invalid number; **6h** limit. |
| **Email issues** | Sender Domains; subject/body limits; list quality. |
| **SMS issues** | Phone Numbers; provisioning and compliance. |
**Tip:** Pair urgency with a clear **deadline** and **why it matters** (“Stay in process for X — complete by Friday”).
### Related
* [Email Templates](contact-blasts) — **Automated** lifecycle mail (separate from one-off blasts).
* [Phone Numbers](phone-numbers)
* [Sender Domains](sender-domains)
* [Outreach](.)
**Help:** [**support@heymilo.ai**](mailto:support@heymilo.ai) or in-app chat.