getmxrr函數有哪些常見的使用方法和技巧？

gitbox 2025-06-12

在php中， getMxrr（）是一個用於獲取指定域名的mx （郵件交換）記錄的函數。 Mx記錄是域名系統（ dns）中的一項記錄類型

基本用法

getmxrr（）函數的基本語法如下：

 <span><span><span class="hljs-keyword">bool</span></span><span> </span><span><span class="hljs-title function_ invoke__">getmxrr</span></span><span> ( </span><span><span class="hljs-keyword">string</span></span><span> </span><span><span class="hljs-variable">$hostname</span></span><span> , </span><span><span class="hljs-keyword">array</span></span><span> &amp;</span><span><span class="hljs-variable">$mxhosts</span></span><span> [, </span><span><span class="hljs-keyword">array</span></span><span> &amp;</span><span><span class="hljs-variable">$weight</span></span><span> = </span><span><span class="hljs-literal">NULL</span></span><span> ] )
</span></span>

參數說明：

$主機名：指定要查詢的域名。
$ mxhosts ：一個數組，返回mx記錄服務器的地址。
$重量（（（（（重量））：返回的數組

返回值：

如果成功，返回true ，並且$ mxhosts和
如果失敗，返回， false ，並且$ mxhosts和$重量數組將為空。

示例代碼：

 <span><span><span class="hljs-meta">&lt;?php</span></span><span>
</span><span><span class="hljs-variable">$hostname</span></span><span> = </span><span><span class="hljs-string">"example.com"</span></span><span>;
</span><span><span class="hljs-variable">$mxhosts</span></span><span> = [];
</span><span><span class="hljs-variable">$weight</span></span><span> = [];

</span><span><span class="hljs-keyword">if</span></span><span> (</span><span><span class="hljs-title function_ invoke__">getmxrr</span></span><span>(</span><span><span class="hljs-variable">$hostname</span></span><span>, </span><span><span class="hljs-variable">$mxhosts</span></span><span>, </span><span><span class="hljs-variable">$weight</span></span><span>)) {
    </span><span><span class="hljs-keyword">echo</span></span><span> </span><span><span class="hljs-string">"MX Records for <span class="hljs-subst">$hostname</span></span></span><span>:\n";
    </span><span><span class="hljs-keyword">foreach</span></span><span> (</span><span><span class="hljs-variable">$mxhosts</span></span><span> </span><span><span class="hljs-keyword">as</span></span><span> </span><span><span class="hljs-variable">$index</span></span><span> =&gt; </span><span><span class="hljs-variable">$host</span></span><span>) {
        </span><span><span class="hljs-keyword">echo</span></span><span> </span><span><span class="hljs-string">"Host: <span class="hljs-subst">$host</span></span></span><span>, Weight: " . </span><span><span class="hljs-variable">$weight</span></span><span>[</span><span><span class="hljs-variable">$index</span></span><span>] . </span><span><span class="hljs-string">"\n"</span></span><span>;
    }
} </span><span><span class="hljs-keyword">else</span></span><span> {
    </span><span><span class="hljs-keyword">echo</span></span><span> </span><span><span class="hljs-string">"Failed to retrieve MX records for <span class="hljs-subst">$hostname</span></span></span><span>.\n";
}
</span><span><span class="hljs-meta">?&gt;</span></span><span>
</span></span>

在上面的代碼中， getMxrr（）會獲取

常見技巧與應用

1。驗證域名是否可接收郵件

通過getMxrr（）函數，開發者可以驗證一個域名是否配置了郵件服務器，從而判斷該域名是否能夠接收郵件。如果獲取到的mx記錄不為空，則說明該域名能夠接收郵件。

 <span><span><span class="hljs-meta">&lt;?php</span></span><span>
</span><span><span class="hljs-function"><span class="hljs-keyword">function</span></span></span><span> </span><span><span class="hljs-title">isMailServerAvailable</span></span><span>(</span><span><span class="hljs-params"><span class="hljs-variable">$domain</span></span></span><span>) {
    </span><span><span class="hljs-variable">$mxhosts</span></span><span> = [];
    </span><span><span class="hljs-keyword">if</span></span><span> (</span><span><span class="hljs-title function_ invoke__">getmxrr</span></span><span>(</span><span><span class="hljs-variable">$domain</span></span><span>, </span><span><span class="hljs-variable">$mxhosts</span></span><span>)) {
        </span><span><span class="hljs-keyword">return</span></span><span> </span><span><span class="hljs-literal">true</span></span><span>;  </span><span><span class="hljs-comment">// &#26377;MX&#35760;&#24405;&#65292;&#34920;&#31034;&#21487;&#20197;&#25509;&#25910;&#37038;&#20214;</span></span><span>
    }
    </span><span><span class="hljs-keyword">return</span></span><span> </span><span><span class="hljs-literal">false</span></span><span>;  </span><span><span class="hljs-comment">// &#26080;MX&#35760;&#24405;&#65292;&#34920;&#31034;&#19981;&#21487;&#25509;&#25910;&#37038;&#20214;</span></span><span>
}

</span><span><span class="hljs-variable">$domain</span></span><span> = </span><span><span class="hljs-string">"example.com"</span></span><span>;
</span><span><span class="hljs-keyword">if</span></span><span> (</span><span><span class="hljs-title function_ invoke__">isMailServerAvailable</span></span><span>(</span><span><span class="hljs-variable">$domain</span></span><span>)) {
    </span><span><span class="hljs-keyword">echo</span></span><span> </span><span><span class="hljs-string">"<span class="hljs-subst">$domain</span></span></span><span> &#21487;&#20197;&#25509;&#25910;&#37038;&#20214;\n";
} </span><span><span class="hljs-keyword">else</span></span><span> {
    </span><span><span class="hljs-keyword">echo</span></span><span> </span><span><span class="hljs-string">"<span class="hljs-subst">$domain</span></span></span><span> &#26080;&#27861;&#25509;&#25910;&#37038;&#20214;\n";
}
</span><span><span class="hljs-meta">?&gt;</span></span><span>
</span></span>

2。查找最優的郵件服務器

根據mx記錄的權重值，優先級較低的服務器會被優先使用。通過getmxrr（）獲取的權重數組，可以幫助開發者找到優先級最高的郵件服務器。，可以幫助開發者找到優先級最高的郵件服務器。

 <span><span><span class="hljs-meta">&lt;?php</span></span><span>
</span><span><span class="hljs-function"><span class="hljs-keyword">function</span></span></span><span> </span><span><span class="hljs-title">getBestMailServer</span></span><span>(</span><span><span class="hljs-params"><span class="hljs-variable">$domain</span></span></span><span>) {
    </span><span><span class="hljs-variable">$mxhosts</span></span><span> = [];
    </span><span><span class="hljs-variable">$weights</span></span><span> = [];
    
    </span><span><span class="hljs-keyword">if</span></span><span> (</span><span><span class="hljs-title function_ invoke__">getmxrr</span></span><span>(</span><span><span class="hljs-variable">$domain</span></span><span>, </span><span><span class="hljs-variable">$mxhosts</span></span><span>, </span><span><span class="hljs-variable">$weights</span></span><span>)) {
        </span><span><span class="hljs-variable">$bestServerIndex</span></span><span> = </span><span><span class="hljs-title function_ invoke__">array_search</span></span><span>(</span><span><span class="hljs-title function_ invoke__">min</span></span><span>(</span><span><span class="hljs-variable">$weights</span></span><span>), </span><span><span class="hljs-variable">$weights</span></span><span>);
        </span><span><span class="hljs-keyword">return</span></span><span> </span><span><span class="hljs-variable">$mxhosts</span></span><span>[</span><span><span class="hljs-variable">$bestServerIndex</span></span><span>];
    }
    
    </span><span><span class="hljs-keyword">return</span></span><span> </span><span><span class="hljs-literal">null</span></span><span>;
}

</span><span><span class="hljs-variable">$domain</span></span><span> = </span><span><span class="hljs-string">"example.com"</span></span><span>;
</span><span><span class="hljs-variable">$bestServer</span></span><span> = </span><span><span class="hljs-title function_ invoke__">getBestMailServer</span></span><span>(</span><span><span class="hljs-variable">$domain</span></span><span>);
</span><span><span class="hljs-keyword">if</span></span><span> (</span><span><span class="hljs-variable">$bestServer</span></span><span>) {
    </span><span><span class="hljs-keyword">echo</span></span><span> </span><span><span class="hljs-string">"&#26368;&#20248;&#30340;&#37038;&#20214;&#26381;&#21153;&#22120;&#26159;: <span class="hljs-subst">$bestServer</span></span></span><span>\n";
} </span><span><span class="hljs-keyword">else</span></span><span> {
    </span><span><span class="hljs-keyword">echo</span></span><span> </span><span><span class="hljs-string">"&#26080;&#27861;&#25214;&#21040;&#37038;&#20214;&#26381;&#21153;&#22120;\n"</span></span><span>;
}
</span><span><span class="hljs-meta">?&gt;</span></span><span>
</span></span>

（（（）來找出最優的郵件服務器。

3。過濾和選擇特定的郵件服務器

在某些情況下，開發者可能只對某些特定的郵件服務器感興趣，比如選擇一個特定區域的郵件服務器或特定類型的服務器。可以在獲取mx，通過簡單的數組過濾來實現這一需求。，通過簡單的數組過濾來實現這一需求。

 <span><span><span class="hljs-meta">&lt;?php</span></span><span>
</span><span><span class="hljs-function"><span class="hljs-keyword">function</span></span></span><span> </span><span><span class="hljs-title">filterMailServers</span></span><span>(</span><span><span class="hljs-params"><span class="hljs-variable">$domain</span></span></span><span>, </span><span><span class="hljs-variable">$filter</span></span><span>) {
    </span><span><span class="hljs-variable">$mxhosts</span></span><span> = [];
    </span><span><span class="hljs-variable">$weights</span></span><span> = [];
    
    </span><span><span class="hljs-keyword">if</span></span><span> (</span><span><span class="hljs-title function_ invoke__">getmxrr</span></span><span>(</span><span><span class="hljs-variable">$domain</span></span><span>, </span><span><span class="hljs-variable">$mxhosts</span></span><span>, </span><span><span class="hljs-variable">$weights</span></span><span>)) {
        </span><span><span class="hljs-variable">$filteredHosts</span></span><span> = </span><span><span class="hljs-title function_ invoke__">array_filter</span></span><span>(</span><span><span class="hljs-variable">$mxhosts</span></span><span>, function(</span><span><span class="hljs-variable">$host</span></span><span>) </span><span><span class="hljs-keyword">use</span></span><span> ($</span><span><span class="hljs-title">filter</span></span><span>) {
            </span><span><span class="hljs-title">return</span></span><span> </span><span><span class="hljs-title">strpos</span></span><span>($</span><span><span class="hljs-title">host</span></span><span>, $</span><span><span class="hljs-title">filter</span></span><span>) !== </span><span><span class="hljs-title">false</span></span><span>;  </span><span><span class="hljs-comment">// &#36807;&#28388;&#20986;&#21253;&#21547;&#25351;&#23450;&#23383;&#31526;&#20018;&#30340;&#37038;&#20214;&#26381;&#21153;&#22120;</span></span><span>
        });
        </span><span><span class="hljs-keyword">return</span></span><span> </span><span><span class="hljs-variable">$filteredHosts</span></span><span>;
    }
    
    </span><span><span class="hljs-keyword">return</span></span><span> [];
}

</span><span><span class="hljs-variable">$domain</span></span><span> = </span><span><span class="hljs-string">"example.com"</span></span><span>;
</span><span><span class="hljs-variable">$filteredServers</span></span><span> = </span><span><span class="hljs-title function_ invoke__">filterMailServers</span></span><span>(</span><span><span class="hljs-variable">$domain</span></span><span>, </span><span><span class="hljs-string">"gmail"</span></span><span>);

</span><span><span class="hljs-keyword">if</span></span><span> (!</span><span><span class="hljs-keyword">empty</span></span><span>(</span><span><span class="hljs-variable">$filteredServers</span></span><span>)) {
    </span><span><span class="hljs-keyword">echo</span></span><span> </span><span><span class="hljs-string">"&#36807;&#28388;&#21518;&#30340;&#37038;&#20214;&#26381;&#21153;&#22120;:\n"</span></span><span>;
    </span><span><span class="hljs-keyword">foreach</span></span><span> (</span><span><span class="hljs-variable">$filteredServers</span></span><span> </span><span><span class="hljs-keyword">as</span></span><span> </span><span><span class="hljs-variable">$server</span></span><span>) {
        </span><span><span class="hljs-keyword">echo</span></span><span> </span><span><span class="hljs-variable">$server</span></span><span> . </span><span><span class="hljs-string">"\n"</span></span><span>;
    }
} </span><span><span class="hljs-keyword">else</span></span><span> {
    </span><span><span class="hljs-keyword">echo</span></span><span> </span><span><span class="hljs-string">"&#26410;&#25214;&#21040;&#31526;&#21512;&#26465;&#20214;&#30340;&#37038;&#20214;&#26381;&#21153;&#22120;\n"</span></span><span>;
}
</span><span><span class="hljs-meta">?&gt;</span></span><span>
</span></span>

在這個示例中， filtermailservers（）函數會過濾出所有包含gmail字符串的郵件服務器。

注意事項

dns查詢限制： getmxrr（）函數依賴於dns查詢的正確性和穩定性。如果dns服務器出現問題，可能會導致查詢失敗。，可能會導致查詢失敗。
結果順序： getmxrr（）返回的mx記錄是按照優先級順序排列的，優先級較低的服務器會出現在前面（即更高優先級）。
非標準返回值：在某些情況下，如果域名沒有配置mx記錄
安全性：儘管getMxrr（）是一個常用的dns查詢工具，但在公，環境中使用時，開發者應該注意避免信息洩露，特別是當暴露在外部系統時。

總結

getMxrr（）是php中一個簡單但功能強大的函數，適用於各種需要獲取和操作mx 記錄的場景。無論是進行郵件驗證、尋找最優郵件服務器，還是實現郵件路由策略， getmxrr（）都能夠提供重要的幫助。通過合理使用它，可以在郵件系統的搭建和維護中提高效率。，可以在郵件系統的搭建和維護中提高效率。

getmxrr