我有一个通信应用程序，每个用户创建一个对应关系并将其发送给多个用户（平均发送我们2-30用户之间），每次发送我打开一个新线程并在以下流程中向用户组发送电子邮件（连接到邮件服务器＆gt;发送＆gt;关闭连接）如下：
public class EmailService {
private String emailProtocol = null;
private String emailHostSMTP = null;
private String senderEmail = null;
private String senderUser = null;
private String senderPassword = null;
private String senderDisplayName = null;
private String emailPort = null;
public void initConfig() {
emailProtocol = GeneralServices.getConfig("emailProtocol");
emailHostSMTP = GeneralServices.getConfig("emailHostSMTP");
senderEmail = GeneralServices.getConfig("senderEmail");
senderUser = GeneralServices.getConfig("senderUser");
senderPassword = GeneralServices.getConfig("senderPassword");
senderDisplayName = GeneralServices.getConfig("senderDisplayName");
emailPort = GeneralServices.getConfig("emailPort");
if (StringUtils.isBlank(emailPort))
emailPort = "587";
}
public void setProps(Properties props) {
props.put("mail.transport.protocol", emailProtocol);
props.put("mail.smtp.host", emailHostSMTP);
props.put("mail.smtp.auth", "true");
props.put("mail.smtp.port", emailPort);
if (ConfigurationUtils.isEnableStartTlsInEmail())
props.put("mail.smtp.starttls.enable", "true");
if (ConfigurationUtils.isEnableDebugInEmail())
props.put("mail.debug", "true");
}
public void sendEmail(String toUser, String subject, String emailHtmlBody, String bannerPath) throws Exception {
try {
if (StringUtils.isBlank(toUser)) {
return;
}
List<String> toUsers = new ArrayList<String>(1);
toUsers.add(toUser);
sendEmail(toUsers, null, null, subject, emailHtmlBody, bannerPath);
} catch (Exception e) {
throw e;
}
}
public void sendEmail(String fromEmail, String fromDisplayName, List<String> toList, List<String> ccList,
String subject, String emailBody, String filePhysicalPath, String fileName, String fileContentType)
throws Exception {
Transport transport = null;
try {
initConfig();
MimeMultipart multipart = new MimeMultipart();
Authenticator authenticator = new SMTPAuthenticator();
MailSSLSocketFactory sslSocketFactory = new MailSSLSocketFactory();
MimeBodyPart bodyPart = new MimeBodyPart();
String html = "";
Properties props = System.getProperties();
setProps(props);
sslSocketFactory.setTrustAllHosts(true);
props.put("mail.smtp.ssl.socketFactory", sslSocketFactory);
Session session = Session.getInstance(props, authenticator);
// session.setDebug(true);
emailBody = emailBody + "<br/><br/>مرسل بواسطة : " + fromDisplayName;
html = "<html><body style='text-align:right'> " + emailBody + " </body></html>";
bodyPart.setContent(html, "text/html; charset=UTF-8");
multipart.addBodyPart(bodyPart);
MimeMessage message = new MimeMessage(session);
message.setFrom(new InternetAddress(senderEmail, fromDisplayName));
message.setReplyTo(new Address[] { new InternetAddress(fromEmail) });
if (toList != null && toList.size() > 0) {
for (String to : toList) {
message.addRecipient(Message.RecipientType.TO, new InternetAddress(to));
}
} else {
throw new Exception("List of users to send email to is empty");
}
if (ccList != null && ccList.size() > 0) {
for (String cc : ccList) {
message.addRecipient(Message.RecipientType.CC, new InternetAddress(cc));
}
}
// attach file
BodyPart mimeBodyPart = new MimeBodyPart();
DataSource source = new FileDataSource(filePhysicalPath);
mimeBodyPart.setDataHandler(new DataHandler(source));
mimeBodyPart.setFileName(MimeUtility.encodeText(fileName, "utf-8", "B"));
multipart.addBodyPart(mimeBodyPart);
// end of file attach
message.setSubject(subject, "UTF-8");
message.setContent(multipart);
message.setSentDate(new Date());
transport = session.getTransport(emailProtocol);
transport.connect(senderEmail, senderPassword);
transport.sendMessage(message, message.getAllRecipients());
} catch (Exception ex) {
throw ex;
} finally {
if (transport != null)
transport.close();
}
}
public void sendEmail(List<String> toList, List<String> ccList, List<String> bccList, String subject,
String emailHtmlBody, String bannerPath) throws Exception {
if ((toList == null || toList.size() == 0) && (ccList == null || ccList.size() == 0)
&& (bccList == null || bccList.size() == 0)) {
return;
}
Transport transport = null;
try {
initConfig();
MimeMultipart multipart = new MimeMultipart();
Authenticator authenticator = new SMTPAuthenticator();
MailSSLSocketFactory sslSocketFactory = new MailSSLSocketFactory();
MimeBodyPart bodyPart = new MimeBodyPart();
String html = "";
Properties props = System.getProperties();
setProps(props);
sslSocketFactory.setTrustAllHosts(true);
props.put("mail.smtp.ssl.socketFactory", sslSocketFactory);
Session session = Session.getInstance(props, authenticator);
html = "<html><body> " + emailHtmlBody + " </body></html>";
bodyPart.setContent(html, "text/html; charset=UTF-8");
multipart.addBodyPart(bodyPart);
// add banner path
bodyPart = new MimeBodyPart();
DataSource ds = new FileDataSource(bannerPath);
bodyPart.setDataHandler(new DataHandler(ds));
bodyPart.setHeader("Content-ID", "<MOAMALAT_LOGO>");
multipart.addBodyPart(bodyPart);
MimeMessage message = new MimeMessage(session);
message.setFrom(new InternetAddress(senderEmail, senderDisplayName));
message.setReplyTo(new Address[] { new InternetAddress(senderEmail) });
if (toList != null && toList.size() > 0) {
for (String email : toList)
message.addRecipient(Message.RecipientType.TO, new InternetAddress(email));
}
if (ccList != null && ccList.size() > 0) {
for (String email : ccList)
message.addRecipient(Message.RecipientType.CC, new InternetAddress(email));
}
if (bccList != null && bccList.size() > 0) {
for (String email : bccList)
message.addRecipient(Message.RecipientType.BCC, new InternetAddress(email));
}
message.setSubject(subject, "UTF-8");
message.setContent(multipart);
message.setSentDate(new Date());
transport = session.getTransport(emailProtocol);
transport.connect(senderEmail, senderPassword);
transport.sendMessage(message, message.getAllRecipients());
} catch (Exception ex) {
throw ex;
} finally {
if (transport != null)
transport.close();
}
}
private class SMTPAuthenticator extends javax.mail.Authenticator {
@Override
public PasswordAuthentication getPasswordAuthentication() {
String username = senderUser;
String password = senderPassword;
return new PasswordAuthentication(username, password);
}
}
}
有时我会收到错误：
com.sun.mail.smtp.SMTPSendFailedException: 421 4.4.2 Message submission rate for this client has exceeded the configured limit
但在与Exchange Server管理员进行审核后，他说我没有发送超出限制的电子邮件。
有时我也会收到错误：
java.net.SocketException: Connection reset
有时我也会得到：
javax.mail.MessagingException: Can't send command to SMTP host,Caused by: java.net.SocketException: Connection closed by remote host
您建议解决上述问题的解决方案是什么？
我读到有些人将传输对象设为静态并只连接到交换服务器一次，然后重复使用它，这有助于解决问题吗？连接打开多长时间？
我还想到了一个解决方案，可以将电子邮件详细信息保存在数据库表中，并让工作类定期批量发送电子邮件。
请告知如何解决此问题。
答案 0 :(得分：2)
我编辑了你第二次声明的 sendEmail 方法（如下所示）。如果您喜欢它，请将相同的技术应用于其他sendEmail方法。
作为一个解决方案，我抓住了sendMessage部分进入cc列表的for循环。因此，对于每个“到”电子邮件和每个相应的“cc”电子邮件，将发送电子邮件。您也必须评估是否缺少cc列表。代码可能没有编译，但你应该看到这一点。
def __multiprocess(las_point_array, point_array, empty, tree):
pool = Pool(os.cpu_count())
args_list = [
[j, point_array, empty, tree]
for j in las_point_array
]
results = pool.map(__pure_calc, args_list)
#close the pool and wait for the work to finish
pool.close()
pool.join()
return results
答案 1 :(得分：2)
以下代码必须只运行一次，而不是每次sendEmail调用：
initConfig()
和
transport = session.getTransport(emailProtocol);
transport.connect(senderEmail, senderPassword);
我会创建一个工厂类，它将初始化并返回一个传输实例，因此我可以使用和重用来维护与MX的多个连接，
设置会话和传输必须在进行任何sendEmail调用之前完成，因此构造函数适合您。
你可以利用会话和传输对象的小对象池，每次调用sendEmail方法都必须从池中获取一个传输实例，并在完成后将其返回池中，这样可以确保在并发请求环境中轻松加载， 进一步推断批量推动限制，首先增加推动之间的时间间隔，减少时间间隔，以便知道接近推送之间的MX准确限制，并将其与推尺寸相关联以定义最终限制。
答案 2 :(得分：1)
根据错误消息：
此客户端的邮件提交率已超过配置 限制
1）。 这可能是由Exchange trotting policy引起的，而here通常是Exchange管理员所不知道的（如trotting policy所述）。
因此，让您的Exchange管理员通过以下方式控制new trotting policy内的 MessageRateLimit ：
Get-ThrottlingPolicy | select Name,MessageRateLimit
因为Microsoft将此参数记录为：
MessageRateLimit参数指定每个消息的数量 可以由POP3或IMAP4客户端提交传输的分钟 使用SMTP。如果客户提交，则会收到暂时性错误 消息的速率超过此参数的值。交换 尝试在以后连接并发送消息。
低值可能会导致此问题。 Exchange管理员还可以仅为您正在使用的此任务用户创建具有更高值的here，这不会导致现有用户出现任何问题（有关示例，请参阅{{3}}）。因此无需更改默认的小跑策略。
更新： 2.） 在您现在检查小跑策略时，另一种解决方案可能是控制/监视SMTP流量的SMTP解决方案。这可能与客户端相关或服务器端相关（取决于您的环境）。这里可能的选择是：防火墙＆amp; AntivirusClients