Mailbox Engine vs. SendOutCards (Promptings): Which Card Program Pays Off?
SendOutCards, now branded Promptings, and Mailbox Engine both send personalized cards and gifts. Compare membership prices, cards included, postcards, automation, QR tracking, and lead-generation tools for real estate and insurance agents.
By the Mailbox Engine team · · 5 min read
Key takeaways
- SendOutCards rebranded as Promptings; memberships are $27, $47, and $112 a month for 5, 15, and 50 cards with stamps included.
- If you only send about 50 cards a month, SendOutCards Pro at $112 costs less than Mailbox Engine Basic with postage ($140.99).
- Mailbox Engine Basic adds unlimited small postcards, and Professional adds QR scan alerts, Nearest Neighbor mailing, and 200 cards a month.
- At 200 cards a month, Mailbox Engine Professional totals $363.99 vs. $520 for a 200-card SendOutCards Gratitude Pack.
SendOutCards has been a go-to for relationship marketers for years, and it now operates as Promptings. Like Mailbox Engine, it sends personalized greeting cards and gifts from an online account, with reminders and automated campaigns to help you remember the people who matter (Promptings).
Where the two differ is what happens beyond the card. Mailbox Engine pairs cards and gifts with unlimited postcards, trackable QR codes, neighbor mailing, and list building, so the same account that thanks a client can also find the next one.
The short answer
Best fit
Choose Mailbox Engine if…
- You want cards and postcards in one plan, with unlimited small postcards included.
- You want to know who scanned your mail so you can call them the same day.
- You want client mail to generate new leads through neighbor mailing and list building.
- You send 100 or more cards a month and want the lowest cost per card.
Also a fit
Choose SendOutCards if…
- You send a few cards a month and want the lowest entry price.
- You want thousands of ready-made card designs to browse.
- You like card credits that roll over month to month.
- Cards and gifts are all you need, without postcards or tracking.
Side-by-side comparison
From each company's public pages, checked October 6, 2026.
| Mailbox Engine | SendOutCards (Promptings) | |
|---|---|---|
| Plans | Basic $99.99/mo, Professional $199.99/mo, no contracts | Casual $27/mo, Advanced $47/mo, Pro $112/mo (pricing) |
| Cards included | 50/mo (Basic) or 200/mo (Professional); allowance resets monthly | 5, 15, or 50/mo with stamps; credits roll over |
| Extra cards | $0.99 (Basic) or $0.79 (Professional) + 82¢ postage | Gratitude Packs: 100 for $290, 200 for $520, 450 for $1,045 (stamps included) |
| Postcards | Unlimited small postcards on every plan; both sizes on Professional | Not listed on pricing page |
| Gifts | Hundreds of personalized gifts; 5 free mugs/mo and wholesale pricing on Professional | Gift catalog with 15% to 30% member discounts |
| Automation | Birthday, anniversary, scheduled follow-ups, nearest neighbor (Pro) | Reminders, campaigns, and automated sending systems |
| Card designs | Ready-made campaign templates; personalize with photos, merge fields, QR codes | Thousands of professionally designed cards; custom card backs |
| Handwriting | Handwriting fonts | Handwriting font and signature add-on, $29 |
| QR tracking | Unique QR per recipient; scan alerts naming the person (Professional) | Not listed on pricing page |
| Lists and lead generation | AI-assisted list builder, Visitor Reveal, Nearest Neighbor (Pro) | Not listed on pricing page |
| Integrations | CRM integrations incl. Follow Up Boss, Zapier, API & webhooks | Built-in card-inclusive CRM |
Pricing: who pays less, and when
This is a case where the answer depends on volume, so here are both sides.
| Monthly volume | Mailbox Engine | SendOutCards |
|---|---|---|
| 5 cards | $104.09 on Basic ($99.99 + $4.10 postage) | $27 on Casual |
| 50 cards | $140.99 on Basic ($99.99 + $41.00 postage) | $112 on Pro |
| 50 cards + 200 small postcards | $270.99 on Basic | Postcards not listed |
| 200 cards | $363.99 on Professional ($199.99 + $164.00 postage) | $520 for a 200-card Gratitude Pack |
Postage is calculated at the 82¢ greeting card rate and 65¢ postcard rate effective July 12, 2026 (USPS). SendOutCards prices include stamps.
Beyond the card: turning thank-yous into leads
A greeting card keeps a relationship warm. The next step is knowing when that relationship turns into business. Mailbox Engine's Professional plan puts a unique QR code on each piece and texts you the name of whoever scans it, so a past client checking their home value becomes a same-day phone call. Our guide to tracking direct mail with QR codes explains the setup.
Professional also includes Nearest Neighbor mailing: when you add a client, up to five nearby homes receive a postcard. For real estate agents, that turns every closing into neighborhood visibility; see just sold postcards and our farming postcards cost guide. Every plan includes the AI-assisted list builder and Visitor Reveal, which identifies website visitors so you can follow up by mail.
Automation and ease of use
Both platforms are built around not forgetting people. Promptings offers reminders, campaigns, and an automated sending system supported by its Gratitude System Expert team (Promptings). Mailbox Engine includes birthday and anniversary automations, scheduled follow-ups, and ready-made campaign templates for birthdays, referrals, reactivations, and client appreciation on every plan. If you would rather hand it off, Done For You setup builds the campaigns for you.
Mailbox Engine also connects to CRMs including Follow Up Boss, plus Zapier and an API, so a closing or a new policy in your CRM can start a campaign without re-entering contacts.
Card designs and templates
SendOutCards' catalog is a genuine strength: thousands of professionally designed cards for birthdays, gratitude, business, and holidays. Mailbox Engine focuses on campaign templates, with the designs personalized with your photos, merge fields, and QR codes. If you need message ideas, start with our what to write in a closing card, home anniversary card messages, and insurance client birthday card messages.
Why relationship mail is worth the spend
Mail from businesses people already know gets read. The USPS Household Diary Study found 59% of households read advertising mail from businesses they use and 16% intend to respond, compared with 23% and 2% from businesses they do not use (USPS HDS FY2023). For insurance agents, that attention matters: J.D. Power found 57% of auto insurance customers shopped in the past year (J.D. Power). Our insurance client retention strategies and sphere of influence marketing guides show how to build a program around those numbers.
Which should you choose?
If you send a modest number of cards and love browsing designs, SendOutCards is an easy, affordable start. If you want one system that sends cards, postcards, and gifts, tells you who is responding, and turns clients into new leads, Mailbox Engine does more for agents whose business runs on referrals and repeat clients.
Compare Mailbox Engine with PostcardMania, thanks.io, Handwrytten, and ProspectsPLUS!, or see the direct mail platform roundup.
Sources & further reading
- 01Promptings (SendOutCards): pricing
- 02Promptings: automated system overview
- 03USPS: new mailing prices for July 2026
- 04USPS Household Diary Study FY2023 (Table 5.11)
- 05NAR 2025 Profile of Home Buyers and Sellers: referrals and repeat use
- 06J.D. Power 2025 U.S. Insurance Shopping Study
- 07Harvard Business Review: the value of keeping the right customers
Frequently asked questions
Is SendOutCards the same as Promptings?
Yes. SendOutCards now operates under the Promptings brand, and its plans are called Gratitude Memberships. The sendoutcards.com site and app remain in use.
Is SendOutCards cheaper than Mailbox Engine?
At low volume, yes. Promptings' Casual membership is $27 a month for 5 cards, and its Pro membership is $112 for 50 cards with stamps. Mailbox Engine costs less once you add postcards or send more cards: 200 cards a month total $363.99 on Professional.
Does SendOutCards offer QR tracking?
QR tracking is not listed on Promptings' pricing page. Mailbox Engine's Professional plan puts a unique QR code on each piece and texts you the name of the person who scanned.
Can I send gifts with both?
Yes. Promptings has a gift catalog with member discounts of 15% to 30%. Mailbox Engine has hundreds of personalized gifts, and Professional includes five free mugs a month and wholesale gift pricing.
Put this on autopilot.
Mailbox Engine personalizes, prints, packs, and mails your cards, postcards, and gifts on schedule — with QR scan tracking built in. Plans start at $99.99/mo.