[Bug] SMTP Configuration Issues and Crash

I'll start by saying I'm probably configuring something wrong (SMTP config included below), but if I enable SMTP notifications, there's a segfault crash when the the STMP notification tries to fire. I've also noticed there's no config entry for STMP user name, so I'm almost certainly doing something wrong or misunderstanding something. I'm using the Docker compose deployment.

**Desktop:**
- OS: Linux host (Ubuntu server 24.04) for Docker compose
- checkrr Version: 3.6.1

**Additional context**
Here's the SMTP portion of the config (I've omitted the rest of the config since it works fine if this is removed, but I can share it upon request). I've anonymized the server and email addresses.

```yaml
notifications:
smtp:
host: "smtp.server.com"
port: 465
auth:
pass: ""
enabled: true
starttls: false
ssl: true
from: "from@server.com" # This address is the same one that would be used as the username for the SMTP authentication
to: "to@server.com"
notificationtypes:
- reacquire
- unknowndetected
- startrun
- endrun
```
I should note I've tried removing the ` starttls: false` line, but it makes no differencet.

And here's the log from the crash:

```shell
Attaching to checkrr
checkrr | time="2026-04-04T01:45:50-04:00" level=warning msg="No Config file specified, trying to load a default..."
checkrr | time="2026-04-04T01:45:50-04:00" level=info msg="Couldn't load config at: ./checkrr.yaml"
checkrr |
checkrr | _| _|
checkrr | _|_|_| _|_|_| _|_| _|_|_| _| _| _| _|_| _| _|_|
checkrr | _| _| _| _|_|_|_| _| _|_| _|_| _|_|
checkrr | _| _| _| _| _| _| _| _| _|
checkrr | _|_|_| _| _| _|_|_| _|_|_| _| _| _| _|
checkrr | Checkrr version 3.6.1
checkrr | Commit: 5132873a0401bfa81492041655d82e3f5b057874
checkrr | Built On: 2026-02-18T02:04:53Z
checkrr | Built By: goreleaser
checkrr | time="2026-04-04T01:45:50-04:00" level=info msg="Found config at: /etc/checkrr.yaml"
checkrr | time="2026-04-04T01:45:50-04:00" level=info msg="Next Run: 2026-04-04 01:46:00 -0400 EDT"
checkrr | [GIN-debug] [WARNING] Creating an Engine instance with the Logger and Recovery middleware already attached.
checkrr |
checkrr | [GIN-debug] [WARNING] Running in "debug" mode. Switch to "release" mode in production.
checkrr | - using env: export GIN_MODE=release
checkrr | - using code: gin.SetMode(gin.ReleaseMode)
checkrr |
checkrr | [GIN-debug] GET /api/files/bad --> github.com/aetaric/checkrr/webserver.getBadFiles (4 handlers)
checkrr | [GIN-debug] POST /api/files/bad --> github.com/aetaric/checkrr/webserver.deleteBadFiles (4 handlers)
checkrr | [GIN-debug] GET /api/stats/current --> github.com/aetaric/checkrr/webserver.getCurrentStats (4 handlers)
checkrr | [GIN-debug] GET /api/stats/historical --> github.com/aetaric/checkrr/webserver.getHistoricalStats (4 handlers)
checkrr | [GIN-debug] GET /api/schedule --> github.com/aetaric/checkrr/webserver.getSchedule (4 handlers)
checkrr | [GIN-debug] POST /api/run --> github.com/aetaric/checkrr/webserver.runCheckrr (4 handlers)
checkrr | time="2026-04-04T01:45:50-04:00" level=info msg="Starting HTTP Webserver on port 8585"
checkrr | [GIN-debug] Listening and serving HTTP on :8585
checkrr | time="2026-04-04T01:46:00-04:00" level=debug msg="Setting Lock to prevent multi-runs"
checkrr | time="2026-04-04T01:46:00-04:00" level=debug msg="Lidarr Path Maps: [map[/library/music/:/library/music/]]"
checkrr | time="2026-04-04T01:46:00-04:00" level=info msg="Lidarr integration not enabled. Files will not be fixed. (if you expected a no-op, this is fine)" Lidarr 'lidarr' Connected=false Startup=true
checkrr | time="2026-04-04T01:46:00-04:00" level=debug msg="Radarr Path Maps: [map[/library/movies/:/library/movies/]]"
checkrr | time="2026-04-04T01:46:00-04:00" level=info msg="Radarr integration not enabled. Files will not be fixed. (if you expected a no-op, this is fine)" Radarr 'radarr' Connected=false Startup=true
checkrr | time="2026-04-04T01:46:00-04:00" level=debug msg="Sonarr Path Maps: [map[/library/tv/:/library/tv/]]"
checkrr | time="2026-04-04T01:46:00-04:00" level=info msg="Sonarr integration not enabled. Files will not be fixed. (if you expected a no-op, this is fine)" Sonarr 'sonarr' Connected=false Startup=true
checkrr | time="2026-04-04T01:46:10-04:00" level=warning msg="SMTP port is not an integer" SMTP Connected=false Startup=true
checkrr | time="2026-04-04T01:46:10-04:00" level=info msg="connected to SMTP" SMTP Connected=true Startup=true
checkrr | panic: runtime error: invalid memory address or nil pointer dereference
checkrr | [signal SIGSEGV: segmentation violation code=0x1 addr=0x28 pc=0xb45963]
checkrr |
checkrr | goroutine 7 [running]:
checkrr | github.com/xhit/go-simple-mail/v2.(*Email).SendEnvelopeFrom(0xc000410fe0?, {0xc000374018?, 0x17?}, 0x0?)
checkrr | /Users/aetaric/go/pkg/mod/github.com/xhit/go-simple-mail/v2@v2.16.0/email.go:762 +0xa3
checkrr | github.com/xhit/go-simple-mail/v2.(*Email).Send(...)
checkrr | /Users/aetaric/go/pkg/mod/github.com/xhit/go-simple-mail/v2@v2.16.0/email.go:737
checkrr | github.com/aetaric/checkrr/notifications.SMTPNotifs.Notify({{0xc0000396c8, 0x13}, {0xc0002f3c28, 0x3}, 0x1, {0x0, 0x0}, {0xc0002feac0, 0x1e}, {0xc0000396e0, ...}, ...}, ...)
checkrr | /Users/aetaric/src/checkrr/notifications/smtp.go:120 +0x7a5
checkrr | github.com/aetaric/checkrr/notifications.Notifications.Notify(...)
checkrr | /Users/aetaric/src/checkrr/notifications/notifications.go:22
checkrr | github.com/aetaric/checkrr/check.(*Checkrr).connectNotifications(0xc0000dc008)
checkrr | /Users/aetaric/src/checkrr/check/checkrr.go:353 +0x4fb
checkrr | github.com/aetaric/checkrr/check.(*Checkrr).Run(0xc0000dc008)
checkrr | /Users/aetaric/src/checkrr/check/checkrr.go:85 +0x2df
checkrr | github.com/robfig/cron/v3.(*Cron).startJob.func1()
checkrr | /Users/aetaric/go/pkg/mod/github.com/robfig/cron/v3@v3.0.1/cron.go:312 +0x55
checkrr | created by github.com/robfig/cron/v3.(*Cron).startJob in goroutine 20
checkrr | /Users/aetaric/go/pkg/mod/github.com/robfig/cron/v3@v3.0.1/cron.go:310 +0x8c
checkrr exited with code 2 (restarting)
```
Any help pointing me in the right direction would be greatly appreciated, otherwise this tool works great, thank you!