diff --git a/go.mod b/go.mod
index 4668415..958399f 100644
--- a/go.mod
+++ b/go.mod
@@ -32,7 +32,6 @@ require (
 	github.com/google/uuid v1.3.0
 	github.com/hashicorp/go-multierror v1.1.0
 	github.com/jaytaylor/html2text v0.0.0-20200412013138-3577fbdbcff7
-	github.com/kr/text v0.2.0 // indirect
 	github.com/mattn/go-isatty v0.0.14
 	github.com/mattn/go-runewidth v0.0.9 // indirect
 	github.com/miekg/dns v1.1.41
@@ -48,9 +47,6 @@ require (
 	golang.org/x/net v0.0.0-20220425223048-2871e0cb64e4
 	golang.org/x/sys v0.0.0-20220111092808-5a964db01320 // indirect
 	golang.org/x/text v0.3.7
-	gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c // indirect
-	gopkg.in/yaml.v2 v2.2.8 // indirect
-	gopkg.in/yaml.v3 v3.0.0-20200615113413-eeeca48fe776 // indirect
 )
 
 replace (
diff --git a/go.sum b/go.sum
index 339422b..1725314 100644
--- a/go.sum
+++ b/go.sum
@@ -24,7 +24,6 @@ github.com/andybalholm/cascadia v1.1.0 h1:BuuO6sSfQNFRu1LppgbD25Hr2vLYW25JvxHs5z
 github.com/andybalholm/cascadia v1.1.0/go.mod h1:GsXiBklL0woXo1j/WYWtSYYC4ouU9PqHO0sqidkEA4Y=
 github.com/antlr/antlr4 v0.0.0-20201029161626-9a95f0cc3d7c h1:j/C2kxPfyE0d87/ggAjIsCV5Cdkqmjb+O0W8W+1J+IY=
 github.com/antlr/antlr4 v0.0.0-20201029161626-9a95f0cc3d7c/go.mod h1:T7PbCXFs94rrTttyxjbyT5+/1V8T2TYDejxUfHJjw1Y=
-github.com/creack/pty v1.1.9/go.mod h1:oKZEueFk5CKHvIhNR5MUki03XCEU+Q6VDXinZuGJ33E=
 github.com/cronokirby/saferith v0.31.0 h1:TIlhldetKLeGAb19bZvWiuwQEzfzwSPthDEyJ9Ah8xs=
 github.com/cronokirby/saferith v0.31.0/go.mod h1:QKJhjoqUtBsXCAVEjw38mFqoi7DebT7kthcD7UzbnoA=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
@@ -64,12 +63,6 @@ github.com/hashicorp/go-multierror v1.1.0/go.mod h1:spPvp8C1qA32ftKqdAHm4hHTbPw+
 github.com/jaytaylor/html2text v0.0.0-20200412013138-3577fbdbcff7 h1:g0fAGBisHaEQ0TRq1iBvemFRf+8AEWEmBESSiWB3Vsc=
 github.com/jaytaylor/html2text v0.0.0-20200412013138-3577fbdbcff7/go.mod h1:CVKlgaMiht+LXvHG173ujK6JUhZXKb2u/BQtjPDIvyk=
 github.com/konsorten/go-windows-terminal-sequences v1.0.1/go.mod h1:T0+1ngSBFLxvqU3pZ+m/2kptfBszLMUkC4ZK/EgS/cQ=
-github.com/kr/pretty v0.2.1 h1:Fmg33tUaq4/8ym9TJN1x7sLJnHVwhP33CNkpYV/7rwI=
-github.com/kr/pretty v0.2.1/go.mod h1:ipq/a2n7PKx3OHsz4KJII5eveXtPO4qwEXGdVfWzfnI=
-github.com/kr/pty v1.1.1/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=
-github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
-github.com/kr/text v0.2.0 h1:5Nx0Ya0ZqY2ygV366QzturHI13Jq95ApcVaJBhpS+AY=
-github.com/kr/text v0.2.0/go.mod h1:eLer722TekiGuMkidMxC/pM04lWEeraHUUmBw8l2grE=
 github.com/mattn/go-isatty v0.0.14 h1:yVuAays6BHfxijgZPzw+3Zlu5yQgKGP2/hcQbHb7S9Y=
 github.com/mattn/go-isatty v0.0.14/go.mod h1:7GGIvUiUoEMVVmxf/4nioHXj79iQHKdU27kJ6hsGG94=
 github.com/mattn/go-runewidth v0.0.7/go.mod h1:H031xJmbD/WCDINGzjvQ9THkh0rPKHF+m2gUSrubnMI=
@@ -163,12 +156,9 @@ golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7/go.mod h1:I/5z698sn9Ka8T
 golang.org/x/xerrors v0.0.0-20191011141410-1b5146add898/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543 h1:E7g+9GITq07hpfrRu66IVDexMakfv52eLZ2CXBWiKr4=
 golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
-gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c h1:Hei/4ADfdWqJk1ZMxUNpqntNwaWcugrBjAiHlqqRiVk=
-gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c/go.mod h1:JHkPIbrfpd72SG/EVd6muEfDQjcINNoR0C8j2r3qZ4Q=
+gopkg.in/yaml.v2 v2.2.2 h1:ZCJp+EgiOT7lHqUV2J862kp8Qj64Jo6az82+3Td9dZw=
 gopkg.in/yaml.v2 v2.2.2/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
-gopkg.in/yaml.v2 v2.2.8 h1:obN1ZagJSUGI0Ek/LBmuj4SNLPfIny3KsKFopxRdj10=
-gopkg.in/yaml.v2 v2.2.8/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
+gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c h1:dUUwHk2QECo/6vqA44rthZ8ie2QXMNeKRTHCNY2nXvo=
 gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
-gopkg.in/yaml.v3 v3.0.0-20200615113413-eeeca48fe776 h1:tQIYjPdBoyREyB9XMu+nnTclpTYkz2zFM+lzLJFO4gQ=
-gopkg.in/yaml.v3 v3.0.0-20200615113413-eeeca48fe776/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
diff --git a/pkg/smtp/user.go b/pkg/smtp/user.go
index abefee7..4699085 100644
--- a/pkg/smtp/user.go
+++ b/pkg/smtp/user.go
@@ -321,16 +321,16 @@ func (su *smtpUser) Send(returnPath string, to []string, messageReader io.Reader
 
 	startTime := time.Now()
 	for isSending && time.Since(startTime) < 90*time.Second {
-		log.Debug("Message is still in send queue, waiting for a bit")
+		log.Warn("Message is still in send queue, waiting for a bit")
 		time.Sleep(15 * time.Second)
 		isSending, wasSent = su.backend.sendRecorder.isSendingOrSent(su.client(), sendRecorderMessageHash)
 	}
 	if isSending {
-		log.Debug("Message is still in send queue, returning error to prevent client from adding it to the sent folder prematurely")
+		log.Warn("Message is still in send queue, returning error to prevent client from adding it to the sent folder prematurely")
 		return errors.New("original message is still being sent")
 	}
 	if wasSent {
-		log.Debug("Message was already sent")
+		log.Warn("Message was already sent")
 		return nil
 	}
 
diff --git a/pkg/store/ulimit.go b/pkg/store/ulimit.go
index 3765773..cbe3461 100644
--- a/pkg/store/ulimit.go
+++ b/pkg/store/ulimit.go
@@ -15,33 +15,36 @@
 // You should have received a copy of the GNU General Public License
 // along with Proton Mail Bridge. If not, see <https://www.gnu.org/licenses/>.
 
+//go:build !windows
+// +build !windows
+
 package store
 
 import (
-	"fmt"
-	"os"
-	"os/exec"
 	"runtime"
-	"strconv"
-	"strings"
+	"syscall"
 )
 
-func uLimit() int {
-	if runtime.GOOS != "darwin" && runtime.GOOS != "linux" {
-		return 0
-	}
-	out, err := exec.Command("bash", "-c", "ulimit -n").Output()
+func getCurrentFDLimit() (int, error) {
+	var limits syscall.Rlimit
+	err := syscall.Getrlimit(syscall.RLIMIT_NOFILE, &limits)
 	if err != nil {
-		log.Print(err)
-		return 0
+		return 0, err
 	}
-	outStr := strings.Trim(string(out), " \n")
-	num, err := strconv.Atoi(outStr)
-	if err != nil {
-		log.Print(err)
-		return 0
+	return int(limits.Cur), nil
+}
+
+func countOpenedFDs(limit int) int {
+	openedFDs := 0
+
+	for i := 0; i < limit; i++ {
+		_, _, err := syscall.Syscall(syscall.SYS_FCNTL, uintptr(i), uintptr(syscall.F_GETFL), 0)
+		if err == 0 {
+			openedFDs++
+		}
 	}
-	return num
+
+	return openedFDs
 }
 
 func isFdCloseToULimit() bool {
@@ -49,16 +52,18 @@ func isFdCloseToULimit() bool {
 		return false
 	}
 
-	pid := fmt.Sprint(os.Getpid())
-	out, err := exec.Command("lsof", "-p", pid).Output() //nolint:gosec
+	limit, err := getCurrentFDLimit()
 	if err != nil {
-		log.Warn("isFdCloseToULimit: ", err)
+		log.WithError(err).Error("Cannot get current FD limit")
 		return false
 	}
-	lines := strings.Split(string(out), "\n")
 
-	fd := len(lines) - 1
-	ulimit := uLimit()
-	log.Info("File descriptor check: num goroutines ", runtime.NumGoroutine(), " fd ", fd, " ulimit ", ulimit)
-	return fd >= int(0.95*float64(ulimit))
+	openedFDs := countOpenedFDs(limit)
+
+	log.
+		WithField("noGoroutines", runtime.NumCgoCall()).
+		WithField("noFDs", openedFDs).
+		WithField("limitFD", limit).
+		Info("File descriptor check")
+	return openedFDs >= int(0.95*float64(limit))
 }