diff --git a/src/apps/mail/Content.cpp b/src/apps/mail/Content.cpp
index 54927c2441..21b5cd7570 100644
--- a/src/apps/mail/Content.cpp
+++ b/src/apps/mail/Content.cpp
@@ -148,7 +148,7 @@ FilterHTMLTag(int32 &first, char **t, char *end)
 	// check for some common entities (in ISO-Latin-1)
 	if (first == '&') {
 		// filter out and convert decimal values
-		if (a[1] == '#' && sscanf(a + 2, "%ld;", &first) == 1) {
+		if (a[1] == '#' && sscanf(a + 2, "%" B_SCNd32 ";", &first) == 1) {
 			t[0] += strchr(a, ';') - a;
 			return false;
 		}
@@ -932,11 +932,11 @@ TTextView::UpdateFont(const BFont* newFont)
 	fFont = *newFont;
 
 	// update the text run array safely with new font
-	text_run_array *runArray = RunArray(0, LONG_MAX);
+	text_run_array *runArray = RunArray(0, INT32_MAX);
 	for (int i = 0; i < runArray->count; i++)
 		runArray->runs[i].font = *newFont;
 
-	SetRunArray(0, LONG_MAX, runArray);
+	SetRunArray(0, INT32_MAX, runArray);
 	FreeRunArray(runArray);
 }
 
@@ -1917,7 +1917,7 @@ TTextView::Open(hyper_text *enclosure)
 						strcpy(baseName, enclosure->name ? enclosure->name : "enclosure");
 						strcpy(name, baseName);
 						for (int32 index = 0; dir.Contains(name); index++)
-							sprintf(name, "%s_%ld", baseName, index);
+							sprintf(name, "%s_%" B_PRId32, baseName, index);
 
 						BEntry entry(path.Path());
 						entry_ref ref;
diff --git a/src/apps/mail/Header.cpp b/src/apps/mail/Header.cpp
index 60530c83b7..2fc6165461 100644
--- a/src/apps/mail/Header.cpp
+++ b/src/apps/mail/Header.cpp
@@ -348,7 +348,7 @@ THeaderView::THeaderView(BRect rect, BRect windowRect, bool incoming,
 				fAccountMenu->AddItem(
 					item = new BMenuItem(B_TRANSLATE("<none>"), NULL));
 				item->SetEnabled(false);
-				fAccountID = ~0UL;
+				fAccountID = ~(int32)0;
 			}
 			// default account is invalid, set to marked
 			// TODO: do this differently, no casting and knowledge
@@ -1093,7 +1093,7 @@ QPopupMenu::AddPersonItem(const entry_ref *ref, ino_t node, BString &name,
 
 	if (!parentMenu->AddItem(newItem, index + 1)) {
 		fprintf (stderr, "QPopupMenu::AddPersonItem: Unable to add menu "
-			"item \"%s\" at index %ld.\n", sortKey.String(), index + 1);
+			"item \"%s\" at index %" B_PRId32 ".\n", sortKey.String(), index + 1);
 		delete newItem;
 	}
 }
diff --git a/src/apps/mail/MailWindow.cpp b/src/apps/mail/MailWindow.cpp
index f9879d6825..28620739ac 100644
--- a/src/apps/mail/MailWindow.cpp
+++ b/src/apps/mail/MailWindow.cpp
@@ -2396,7 +2396,7 @@ TMailWindow::Send(bool now)
 
 			char versionString[255];
 			sprintf(versionString,
-				"Mail/Haiku %ld.%ld.%ld",
+				"Mail/Haiku %" B_PRIu32 ".%" B_PRIu32 ".%" B_PRIu32,
 				info.major, info.middle, info.minor);
 			fMail->SetHeaderField("X-Mailer", versionString);
 		}
@@ -2578,7 +2578,7 @@ TMailWindow::SaveAsDraft()
 					if (status == B_OK)
 						break;
 					char appendix[B_FILE_NAME_LENGTH];
-					sprintf(appendix, " %ld", i++);
+					sprintf(appendix, " %" B_PRId32, i++);
 					int32 pos = min_c(sizeof(fileName) - strlen(appendix),
 						originalLength);
 					sprintf(fileName + pos, "%s", appendix);
@@ -2746,8 +2746,8 @@ TMailWindow::TrainMessageAs(const char *CommandWord)
 ErrorExit:
 	beep();
 	sprintf(errorString, "Unable to train the message file \"%s\" as %s.  "
-		"Possibly useful error code: %s (%ld).",
-		filePath.Path(), CommandWord, strerror (errorCode), errorCode);
+		"Possibly useful error code: %s (%" B_PRId32 ").",
+		filePath.Path(), CommandWord, strerror(errorCode), errorCode);
 	BAlert* alert = new BAlert("", errorString,	B_TRANSLATE("OK"));
 	alert->SetFlags(alert->Flags() | B_CLOSE_ON_ESCAPE);
 	alert->Go();
@@ -2921,7 +2921,7 @@ TMailWindow::OpenMessage(const entry_ref *ref, uint32 characterSetForDecoding)
 		//	Put the addresses in the 'Save Address' Menu
 		//
 		BMenuItem *item;
-		while ((item = fSaveAddrMenu->RemoveItem(0L)) != NULL)
+		while ((item = fSaveAddrMenu->RemoveItem((int32)0)) != NULL)
 			delete item;
 
 		// create the list of addresses
@@ -2935,7 +2935,7 @@ TMailWindow::OpenMessage(const entry_ref *ref, uint32 characterSetForDecoding)
 		BMessage *msg;
 
 		for (int32 i = addressList.CountItems(); i-- > 0;) {
-			char *address = (char *)addressList.RemoveItem(0L);
+			char *address = (char *)addressList.RemoveItem((int32)0);
 
 			// insert the new address in alphabetical order
 			int32 index = 0;
diff --git a/src/apps/mail/Prefs.cpp b/src/apps/mail/Prefs.cpp
index 8611f1f917..45b32cd151 100644
--- a/src/apps/mail/Prefs.cpp
+++ b/src/apps/mail/Prefs.cpp
@@ -338,7 +338,7 @@ TPrefsWindow::MessageReceived(BMessage* msg)
 
 				fNewFont->SetSize(old_size);
 				if (revert) {
-					sprintf(label, "%ld", old_size);
+					sprintf(label, "%" B_PRId32, old_size);
 					item = fSizeMenu->FindItem(label);
 					if (item != NULL)
 						item->SetMarked(true);
@@ -759,7 +759,7 @@ TPrefsWindow::_BuildSizeMenu(BFont* font)
 	for (loop = 0; loop < sizeof(sizes) / sizeof(int32); loop++) {
 		msg = new BMessage(P_SIZE);
 		msg->AddInt32("size", sizes[loop]);
-		sprintf(label, "%ld", sizes[loop]);
+		sprintf(label, "%" B_PRId32, sizes[loop]);
 		menu->AddItem(item = new BMenuItem(label, msg));
 		if (sizes[loop] == (int32)size)
 			item->SetMarked(true);
diff --git a/src/apps/mail/Signature.cpp b/src/apps/mail/Signature.cpp
index 48a02034f1..dc8bcf949e 100644
--- a/src/apps/mail/Signature.cpp
+++ b/src/apps/mail/Signature.cpp
@@ -369,7 +369,7 @@ TSignatureWindow::Save()
 
 		fFile = new BFile();
 		while(true) {
-			sprintf(name, "signature_%ld", index++);
+			sprintf(name, "signature_%" B_PRId32, index++);
 			if ((result = dir.CreateFile(name, fFile, true)) == B_NO_ERROR)
 				break;
 			if (result != EEXIST)
diff --git a/src/apps/mail/Status.cpp b/src/apps/mail/Status.cpp
index 544646f9d1..7acee481a2 100644
--- a/src/apps/mail/Status.cpp
+++ b/src/apps/mail/Status.cpp
@@ -165,7 +165,7 @@ TStatusWindow::MessageReceived(BMessage* msg)
 							break;
 						if (result != EEXIST)
 							goto err_exit;
-						sprintf(newName, "%s_%ld", name, index++);
+						sprintf(newName, "%s_%" B_PRId32, name, index++);
 					}
 					dir.FindEntry(newName, &entry);
 					node = new BNodeInfo(&file);
diff --git a/src/kits/mail/MailAttachment.cpp b/src/kits/mail/MailAttachment.cpp
index 057427e2cc..be734bfb56 100644
--- a/src/kits/mail/MailAttachment.cpp
+++ b/src/kits/mail/MailAttachment.cpp
@@ -320,7 +320,7 @@ BSimpleMailAttachment::SetToRFC822(BPositionIO *data, size_t length,
 	BMailComponent::SetToRFC822(data, length, parseNow);
 
 	// this actually happens...
-	if (data->Position() - position > length)
+	if (data->Position() - position > (off_t)length)
 		return B_ERROR;
 
 	length -= (data->Position() - position);
@@ -519,8 +519,8 @@ BAttributedMailAttachment::SetTo(BFile *file, bool deleteFileWhenDone)
 	// Also, we have the make up the boundary out of whole cloth
 	// This is likely to give a completely random string
 	BString boundary;
-	boundary << "BFile--" << (int32(file) ^ time(NULL)) << "-"
-		<< ~((int32)file ^ (int32)&fStatus ^ (int32)&_attributes) << "--";
+	boundary << "BFile--" << ((long)file ^ time(NULL)) << "-"
+		<< ~((long)file ^ (long)&fStatus ^ (long)&_attributes) << "--";
 	fContainer->SetBoundary(boundary.String());
 
 	return fStatus = B_OK;
@@ -558,8 +558,8 @@ BAttributedMailAttachment::SetTo(entry_ref *ref)
 			buffer[i] = '_';
 	}
 	buffer[32] = '\0';
-	boundary << "BFile-" << buffer << "--" << ((int32)_data ^ time(NULL))
-		<< "-" << ~((int32)_data ^ (int32)&buffer ^ (int32)&_attributes)
+	boundary << "BFile-" << buffer << "--" << ((long)_data ^ time(NULL))
+		<< "-" << ~((long)_data ^ (long)&buffer ^ (long)&_attributes)
 		<< "--";
 	fContainer->SetBoundary(boundary.String());
 
diff --git a/src/kits/mail/MailContainer.cpp b/src/kits/mail/MailContainer.cpp
index a348b41769..97f07ebadb 100644
--- a/src/kits/mail/MailContainer.cpp
+++ b/src/kits/mail/MailContainer.cpp
@@ -425,8 +425,10 @@ status_t BMIMEMultipartMailContainer::RenderToRFC822(BPositionIO *render_to) {
 			ssize_t amountWritten, length;
 			message_part *part = (message_part *)_components_in_raw.ItemAt(i);
 
-			for (off_t begin = part->start; begin < part->end; begin += sizeof(buffer)) {
-				length = ((part->end - begin) >= sizeof(buffer)) ? sizeof(buffer) : (part->end - begin);
+			for (off_t begin = part->start; begin < part->end;
+				begin += sizeof(buffer)) {
+				length = (((off_t)part->end - begin) >= (off_t)sizeof(buffer))
+					? sizeof(buffer) : (part->end - begin);
 
 				_io_data->ReadAt(begin,buffer,length);
 				amountWritten = render_to->Write(buffer,length);
diff --git a/src/kits/mail/MailMessage.cpp b/src/kits/mail/MailMessage.cpp
index e91139f5b7..abf7de28b1 100644
--- a/src/kits/mail/MailMessage.cpp
+++ b/src/kits/mail/MailMessage.cpp
@@ -122,7 +122,7 @@ BEmailMessage::ReplyMessage(mail_reply_to_mode replyTo, bool accountFromMail,
 		BString cc;
 
 		for (int32 i = list.CountItems(); i-- > 0;) {
-			char *address = (char *)list.RemoveItem(0L);
+			char *address = (char *)list.RemoveItem((int32)0);
 
 			// add everything which is not the sender and not already in the list
 			if (sender.ICompare(address) && cc.FindFirst(address) < 0) {
@@ -731,7 +731,7 @@ BEmailMessage::RenderToRFC822(BPositionIO *file)
 
 	BString recipients;
 	for (int32 i = recipientList.CountItems(); i-- > 0;) {
-		char *address = (char *)recipientList.RemoveItem(0L);
+		char *address = (char *)recipientList.RemoveItem((int32)0);
 
 		recipients << '<' << address << '>';
 		if (i)
diff --git a/src/kits/mail/mail_util.cpp b/src/kits/mail/mail_util.cpp
index 8d8c86e0a2..e7ea0a6cd6 100644
--- a/src/kits/mail/mail_util.cpp
+++ b/src/kits/mail/mail_util.cpp
@@ -681,7 +681,7 @@ utf8_to_rfc2047 (char **bufp, ssize_t length, uint32 charset, char encoding)
 		}
 	}
 
-	while ((currentWord = (struct word *)words.RemoveItem(0L)) != NULL) {
+	while ((currentWord = (struct word *)words.RemoveItem((int32)0)) != NULL) {
 		if ((encoding != quoted_printable && encoding != base64) ||
 		!currentWord->needsEncoding) {
 			rfc2047.Append (currentWord->convertedWord);